{"id":548,"date":"2026-07-24T18:23:42","date_gmt":"2026-07-24T23:23:42","guid":{"rendered":"http:\/\/blog.misumiusa.com\/?p=548"},"modified":"2026-07-24T18:23:43","modified_gmt":"2026-07-24T23:23:43","slug":"how-to-choose-between-linear-shafts-posts-rotary-shafts","status":"publish","type":"post","link":"https:\/\/blog.misumiusa.com\/how-to-choose-between-linear-shafts-posts-rotary-shafts\/","title":{"rendered":"Linear shafts vs. posts vs. rotary shafts: differences, uses, and how to choose"},"content":{"rendered":"\n
Updated July 24, 2026.<\/p>\n\n\n\n\n\n\n
Linear Shafts vs. Posts vs. Rotary Shafts: Differences, Uses & Selection Guide | MISUMI<\/title>\n<meta name=\"description\" content=\"Learn the key differences between linear shafts, posts (standoffs), and rotary shafts \u2014 how each works, what motion type each supports, real-world use cases, and how to choose the right one for your application.\">\n<meta name=\"keywords\" content=\"linear shaft, rotary shaft, post standoff, linear shaft vs rotary shaft, how to choose linear shaft, shaft selection guide, strut post, hex post, sliding motion shaft, power transmission shaft, MISUMI linear shafts, MISUMI rotary shafts, MISUMI posts\">\n<link rel=\"canonical\" href=\"https:\/\/blog.misumiusa.com\/how-to-choose-between-linear-shafts-posts-rotary-shafts\/\">\n\n<meta property=\"og:type\" content=\"article\">\n<meta property=\"og:title\" content=\"Linear Shafts vs. Posts vs. Rotary Shafts: Differences, Uses & Selection Guide | MISUMI\">\n<meta property=\"og:description\" content=\"Learn the differences between linear shafts, posts, and rotary shafts \u2014 how each works, what motion type each supports, real-world use cases, and how to select the right one.\">\n<meta property=\"og:url\" content=\"https:\/\/blog.misumiusa.com\/how-to-choose-between-linear-shafts-posts-rotary-shafts\/\">\n<meta property=\"og:site_name\" content=\"MISUMI Mech Lab Blog\">\n<meta property=\"article:published_time\" content=\"2021-01-19\">\n<meta property=\"article:modified_time\" content=\"2026-07-24\">\n<meta property=\"article:section\" content=\"Mechanical Design\">\n<meta property=\"article:tag\" content=\"linear shafts, rotary shafts, posts, standoffs, shaft selection, sliding motion, power transmission, machine design\">\n\n<meta name=\"twitter:card\" content=\"summary_large_image\">\n<meta name=\"twitter:title\" content=\"Linear Shafts vs. Posts vs. Rotary Shafts: Differences, Uses & Selection Guide | MISUMI\">\n<meta name=\"twitter:description\" content=\"Linear shafts guide sliding motion, rotary shafts transmit power, posts position components. Learn when to use each with use cases and a selection guide.\">\n\n<script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"Article\",\n \"headline\": \"Linear Shafts vs. Posts vs. Rotary Shafts: Differences, Uses and Selection Guide\",\n \"description\": \"A guide to understanding the differences between linear shafts, posts (standoffs), and rotary shafts \u2014 including how each works, motion types supported, real-world use cases, and how to select the right option for your application.\",\n \"datePublished\": \"2021-01-19\",\n \"dateModified\": \"2026-07-24\",\n \"author\": {\"@type\": \"Person\", \"name\": \"Carlicia Layosa\", \"url\": \"https:\/\/blog.misumiusa.com\/author\/clayosa\/\"},\n \"publisher\": {\"@type\": \"Organization\", \"name\": \"MISUMI\", \"url\": \"https:\/\/us.misumi-ec.com\"},\n \"mainEntityOfPage\": {\"@type\": \"WebPage\", \"@id\": \"https:\/\/blog.misumiusa.com\/how-to-choose-between-linear-shafts-posts-rotary-shafts\/\"}\n}\n<\/script>\n\n<script type=\"application\/ld+json\">\n{\n \"@context\": \"https:\/\/schema.org\",\n \"@type\": \"FAQPage\",\n \"mainEntity\": [\n {\n \"@type\": \"Question\",\n \"name\": \"What is a linear shaft and what is it used for?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"A linear shaft is a precision-ground cylindrical rod used to guide and support sliding motion. It does not transmit power itself \u2014 an actuator or drive mechanism does the work. Linear shafts are used with linear bushings or bearings to constrain and guide a carriage or load along a straight path. Shaft size and tolerance are determined by load requirements and required precision.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What is the difference between a linear shaft and a rotary shaft?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"A linear shaft guides sliding (translating) motion and does not rotate or transmit power \u2014 it is a passive support member. A rotary shaft rotates to transmit torque and power from a motor or drive source to another component. Linear shafts are sized by load and precision requirements; rotary shafts are sized by the torque and power they must transmit.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What is a post or standoff used for in machine design?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"A post (also called a standoff or strut post) is a cylindrical, hex, or square bar fixed at one end to a base, used to position, space, or support components in a machine assembly. Posts can serve as pivot points for rotating components, separators between two structural members, or mounting surfaces for sensors, brackets, or guides.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"How do I choose between a linear shaft, post, and rotary shaft?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"Identify the type of motion required. If you need guided sliding or translating motion, use a linear shaft. If you need to transmit rotary power or torque over a distance, use a rotary shaft. If you need to position a component, create a pivot point for rotation around a fixed axis, or space structural members, use a post.\"\n }\n },\n {\n \"@type\": \"Question\",\n \"name\": \"What materials and configurations are available for MISUMI linear shafts?\",\n \"acceptedAnswer\": {\n \"@type\": \"Answer\",\n \"text\": \"MISUMI linear shafts are available in carbon steel and stainless steel, with configurable diameters, lengths, end treatments, and surface treatments including hard chrome plating. They can be configured in 1mm length increments directly on the MISUMI website.\"\n }\n }\n ]\n}\n<\/script>\n\n<style>\n *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }\n body { font-size: 17px; line-height: 1.75; color: #1a1a18; background: #ffffff; padding: 2.5rem 1.5rem 4rem; }\n .byline { display: flex; align-items: center; gap: 10px; font-size: 13px; color: #666; margin-bottom: 2rem; flex-wrap: wrap; }\n .byline-dot { color: #ccc; }\n h1 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 700; line-height: 1.25; letter-spacing: -0.02em; color: #0d0d0b; margin-bottom: 0.75rem; }\n .intro { font-size: 1.05rem; color: #444; margin-bottom: 2rem; border-left: 3px solid #FFD700; padding-left: 1rem; }\n\n \/* \u2500\u2500 TOC \u2500\u2500 *\/\n .toc { background: #f7f5f0; border: 1px solid #e8e4da; border-radius: 6px; padding: 1.25rem 1.5rem; margin: 0 0 2.5rem; font-size: 14px; }\n .toc-title { font-weight: 700; font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; 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}\n .decision-card { border: 1px solid #e0dcd4; border-radius: 8px; overflow: hidden; }\n .decision-card-header { background: #FFD700; color: #1a1a18; padding: 0.75rem 1rem; font-weight: 700; font-size: 14px; }\n .decision-card-body { background: #fffef0; padding: 0.85rem 1rem; font-size: 13px; color: #3a3000; line-height: 1.6; }\n .decision-card-body strong { display: block; color: #1a1a18; margin-bottom: 0.25rem; }\n\n \/* \u2500\u2500 Comparison table \u2500\u2500 *\/\n .spec-table { width: 100%; border-collapse: collapse; font-size: 14px; margin: 1rem 0 1.5rem; }\n .spec-table th { font-weight: 700; padding: 10px 12px; font-size: 13px; }\n .spec-table th.prop-col { text-align: left; background: #f2f0eb; color: #555; border-bottom: 2px solid #ddd; }\n .spec-table th.data-col { background: #FFD700; color: #1a1a18; border-bottom: 2px solid #e6c200; text-align: center; }\n .spec-table td { padding: 9px 12px; border-bottom: 1px solid #eee; vertical-align: top; font-size: 14px; }\n .spec-table td.prop-col { font-weight: 600; color: #333; background: #fafaf8; font-size: 13px; }\n .spec-table td.data-col { text-align: center; background: #fffef0; }\n .spec-table tr:last-child td { border-bottom: none; }\n\n \/* \u2500\u2500 Feature list \u2500\u2500 *\/\n .feature-list { list-style: none; padding: 0; margin: 0.75rem 0; display: flex; flex-direction: column; gap: 0.5rem; }\n .feature-list li { display: flex; align-items: flex-start; gap: 10px; font-size: 15px; color: #2a2a27; line-height: 1.55; }\n .feature-bullet { background: #FFD700; color: #1a1a18; font-size: 10px; font-weight: 800; border-radius: 3px; padding: 2px 6px; margin-top: 4px; flex-shrink: 0; }\n\n \/* \u2500\u2500 Callouts \u2500\u2500 *\/\n .callout { background: #fffce6; border: 1px solid #ffe566; border-left: 4px solid #FFD700; border-radius: 0 6px 6px 0; padding: 1rem 1.25rem; font-size: 14px; color: #3a3000; margin: 1.5rem 0; line-height: 1.6; }\n .callout strong { color: #7a6000; }\n .callout-note { background: #f0f5ff; border-color: #b8cff5; border-left-color: #1a56a0; color: #1a2c4a; }\n .callout-note strong { color: #1a56a0; }\n\n \/* \u2500\u2500 CTA \u2500\u2500 *\/\n .cta-strip { display: flex; align-items: center; gap: 0.75rem; flex-wrap: wrap; margin: 1.25rem 0; }\n .cta-btn { display: inline-block; background: #FFD700; color: #1a1a18; font-size: 13px; font-weight: 700; padding: 10px 20px; border-radius: 4px; text-decoration: none; letter-spacing: 0.01em; transition: background 0.15s; white-space: nowrap; }\n .cta-btn:hover { background: #e6c200; }\n .cta-btn-outline { background: transparent; color: #1a56a0; border: 1px solid #1a56a0; }\n .cta-btn-outline:hover { background: #f0f5ff; }\n\n \/* \u2500\u2500 Footer \u2500\u2500 *\/\n .post-footer { margin-top: 4rem; padding-top: 2rem; border-top: 2px solid #1a1a18; }\n .post-footer-title { font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; font-weight: 700; color: #888; margin-bottom: 0.5rem; }\n .post-footer-note { font-size: 14px; color: #555; line-height: 1.6; }\n .tag-list { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 1rem; }\n .tag { font-size: 12px; background: #f2f0eb; color: #555; padding: 3px 10px; border-radius: 100px; border: 1px solid #e0dcd4; }\n a { color: #1a56a0; }\n a:hover { color: #0e3870; }\n<\/style>\n\n\n\n<p class=\"intro\">Linear shafts, posts, and rotary shafts are all cylindrical components found in machine assemblies\u2014but they serve fundamentally different purposes. This guide explains how each works, what type of motion each supports, real-world use cases by industry, and a simple framework for selecting the right one for your application.<\/p>\n\n<nav class=\"toc\" aria-label=\"Table of contents\">\n <div class=\"toc-title\">Jump to a section<\/div>\n <ol>\n <li><a href=\"#linear-shaft\">Linear shafts<\/a><\/li>\n <li><a href=\"#posts\">Posts (standoffs)<\/a><\/li>\n <li><a href=\"#rotary-shaft\">Rotary shafts<\/a><\/li>\n <li><a href=\"#comparison\">Side-by-side comparison<\/a><\/li>\n <li><a href=\"#how-to-choose\">How to choose<\/a><\/li>\n <li><a href=\"#sizing\">Sizing considerations<\/a><\/li>\n <\/ol>\n<\/nav>\n\n<p>Linear shafts, posts, and rotary shafts are used when you need to control some type of motion: linear, rotary, or a combination of the two. Before we dive into the motion aspects, let\u2019s take a look at how each option works.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"linear-shaft\">Linear shafts<\/h2>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column is-vertically-aligned-center\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" width=\"815\" height=\"689\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-3.jpg\" alt=\"\" class=\"wp-image-10018\" srcset=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-3.jpg 815w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-3-300x254.jpg 300w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-3-150x127.jpg 150w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-3-768x649.jpg 768w\" sizes=\"(max-width: 815px) 100vw, 815px\" \/><\/figure><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" width=\"608\" height=\"654\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Linear-Bushing-and-Shafts-Example-inCAD-Library-Motion.gif\" alt=\"\" class=\"wp-image-10025\"\/><figcaption>Actuator in motion<\/figcaption><\/figure><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"shaft-card\">\n <div class=\"shaft-card-label\">Supports sliding motion<\/div>\n <div class=\"shaft-card-title\"><a href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0100000000\/M0101000000\/\" target=\"_blank\" rel=\"noopener\">Linear Shafts<\/a><\/div>\n <p>The term \u201clinear shaft\u201d can be a little misleading, as the shaft isn’t actually doing any work\u2014it’s just there for support. A linear shaft is used when a sliding motion is needed, especially when that motion needs to be guided and fine-tuned. The shaft acts as a precision track along which a carriage, bushing, or bearing block slides. An actuator (pneumatic, electric, hydraulic, or manual) provides the driving force; the linear shaft and its mating <a href=\"https:\/\/us.misumi-ec.com\/blog\/sliding-guides-part-1\/\" target=\"_blank\" rel=\"noopener\">sliding guides<\/a> constrain the motion to a straight, accurate path. The example above shows the actuator doing the work of lifting the load and the linear shafts and bushings supporting.<\/p>\n <p>Shaft diameter and tolerance class are determined by the applied load, required travel precision, and deflection limits.\/p>\n<\/p><\/div>\n\n<ul class=\"feature-list\">\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Motion type:<\/strong> linear (sliding \/ translating)<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Active or passive:<\/strong> passive\u2014guides motion, does not drive it<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Mating components:<\/strong> linear bushings, linear bearings, shaft supports, end supports<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Sizing driver:<\/strong> applied load, deflection limit, required precision<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Typical materials:<\/strong> carbon steel (hard chrome plated), stainless steel<\/div><\/li>\n<\/ul>\n\n<h3>Linear shaft use cases<\/h3>\n\n<div class=\"usecase-grid\">\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Semiconductor<\/div>\n <div class=\"usecase-card-desc\">Wafer handling gantries where a Z-axis carriage must travel vertically with micron-level repeatability<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Medical<\/div>\n <div class=\"usecase-card-desc\">Lab automation dispensers and pipetting systems requiring smooth, precise linear stroke movement<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Packaging<\/div>\n <div class=\"usecase-card-desc\">Pick-and-place tooling guided on linear shafts to position items accurately on a moving conveyor<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Automotive<\/div>\n <div class=\"usecase-card-desc\">Fixture slides in body-in-white assembly where clamps must retract and extend repeatably on guided rails<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Warehouse automation<\/div>\n <div class=\"usecase-card-desc\">Vertical sorter lift mechanisms where guided vertical travel and smooth carriage action are critical<\/div>\n <\/div>\n<\/div>\n\n<div class=\"cta-strip\">\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0100000000\/M0101000000\/\" target=\"_blank\" rel=\"noopener\">Browse MISUMI linear shafts<\/a>\n <a class=\"cta-btn cta-btn-outline\" href=\"https:\/\/us.misumi-ec.com\/blog\/sliding-guides-part-1\/\" target=\"_blank\" rel=\"noopener\">Sliding guides overview \u2192<\/a>\n<\/div>\n\n\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"posts\">Posts (standoffs)<\/h2>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" width=\"892\" height=\"741\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-1.jpg\" alt=\"\" class=\"wp-image-10019\" srcset=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-1.jpg 892w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-1-300x249.jpg 300w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-1-150x125.jpg 150w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-1-768x638.jpg 768w\" sizes=\"(max-width: 892px) 100vw, 892px\" \/><\/figure><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Hex-Posts-Example-inCAD-Library-Motion.gif\" alt=\"\" class=\"wp-image-10021\" width=\"321\" height=\"308\"\/><figcaption>Hex posts being used in assembly<\/figcaption><\/figure><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"shaft-card\">\n <div class=\"shaft-card-label\">Positions & spaces components<\/div>\n <div class=\"shaft-card-title\"><a href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M1500000000\/M1509000000\/M1509010000\/\" target=\"_blank\" rel=\"noopener\">Posts \/ Standoffs<\/a><\/div>\n <p>A post, also called a standoff or strut post, is exactly what it sounds like: a cylindrical bar fixed at one end to a base that has something that rotates around it. Its purpose is to <strong>position, separate, or support components<\/strong> within a machine assembly at a defined height or spacing. The above example shows hex posts being used in an assembly.<\/p>\n <p>Posts are available in round, hex, and square cross-sections. Hex and square posts provide a wrench flat, making them easy to install and torque without slipping. They can serve as pivot points for components that need to rotate around a fixed axis (like an idler pulley or a hinged guard), as spacers between structural plates, or as adjustable height standoffs for mounting brackets, sensors, and other accessories.<\/p>\n<\/div>\n\n<ul class=\"feature-list\">\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Motion type:<\/strong> none (structural) or rotation-around-post as fixed pivot<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Active or passive:<\/strong> fully passive\u2014structural and positioning only<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Available cross-sections:<\/strong> round, hex, square<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Sizing driver:<\/strong> required height\/spacing, load in compression or bending, thread specification<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Typical materials:<\/strong> carbon steel, stainless steel, aluminum<\/div><\/li>\n<\/ul>\n\n<h3>Post use cases<\/h3>\n\n<div class=\"usecase-grid\">\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">General automation<\/div>\n <div class=\"usecase-card-desc\">Hex posts used to mount a sensor bracket at a precise standoff distance from a machine frame, with clean wrenching surfaces<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Assembly fixtures<\/div>\n <div class=\"usecase-card-desc\">Round strut posts as idler pulley pivots in a belt-driven conveyor\u2014the belt wraps the idler which rotates freely around the fixed post<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Medical \/ lab<\/div>\n <div class=\"usecase-card-desc\">Optical posts and standoffs on breadboard assemblies for positioning lenses, mirrors, and detectors at fixed heights<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Electronics assembly<\/div>\n <div class=\"usecase-card-desc\">PCB standoffs separating a circuit board from an enclosure base plate at the required clearance height<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Structural framing<\/div>\n <div class=\"usecase-card-desc\">Square posts connecting upper and lower plates in a fixture or machine frame, providing rigid vertical load paths<\/div>\n <\/div>\n<\/div>\n\n<div class=\"cta-strip\">\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M1500000000\/M1509000000\/M1509010000\/\" target=\"_blank\" rel=\"noopener\">Browse MISUMI posts & standoffs<\/a>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"rotary-shaft\">Rotary shafts<\/h2>\n\n\n\n<div class=\"wp-block-columns\">\n<div class=\"wp-block-column\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img loading=\"lazy\" width=\"739\" height=\"589\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Rotary-Shafts-Example-inCAD-Library-1.jpg\" alt=\"\" class=\"wp-image-10026\" srcset=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Rotary-Shafts-Example-inCAD-Library-1.jpg 739w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Rotary-Shafts-Example-inCAD-Library-1-300x239.jpg 300w, https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2021\/01\/Rotary-Shafts-Example-inCAD-Library-1-150x120.jpg 150w\" sizes=\"(max-width: 739px) 100vw, 739px\" \/><\/figure><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column\">\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/blog.misumiusa.com\/wp-content\/uploads\/2014\/09\/Rotary-Shafts-Example-inCAD-Library-Motion-1.gif\" alt=\"\" class=\"wp-image-10027\" width=\"376\" height=\"313\"\/><figcaption>Rotary shaft turning and transmitting power<\/figcaption><\/figure><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"shaft-card\">\n <div class=\"shaft-card-label\">Transmits rotary power<\/div>\n <div class=\"shaft-card-title\"><a href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0800000000\/M0801000000\/M0801010000\/\" target=\"_blank\" rel=\"noopener\">Rotary Shafts<\/a><\/div>\n <p>A rotary shaft transmits torque and power from a motor or drive source to another component. Unlike a linear shaft, it is an <em>active<\/em> member\u2014it rotates and does mechanical work. It can operate alone (like an automotive driveshaft) or as part of a system with <a href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M1000000000\/M1002000000\/\" target=\"_blank\" rel=\"noopener\">pulleys and belts<\/a>, sprockets and chains, or gearboxes. The above example shows a rotary shaft doing the work by turning and transmitting power.<\/p>\n <p>Shaft sizing is determined primarily by the amount of power that needs to be transmitted. Key design considerations include keyway geometry, surface finish at bearing seats, shaft deflection under load, and critical speed at the operating RPM. For applications coupling a rotary shaft to a motor, see the related guide on <a href=\"https:\/\/blog.misumiusa.com\/sizing-timing-belts-and-pulleys\/\" target=\"_blank\" rel=\"noopener\">sizing timing belts and pulleys<\/a>.<\/p>\n<\/div>\n\n<ul class=\"feature-list\">\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Motion type:<\/strong> rotary (torque transmission)<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Active or passive:<\/strong> active\u2014transmits power and torque<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Mating components:<\/strong> couplings, bearings, pulleys, sprockets, gears, keyways, set screws<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Sizing driver:<\/strong> transmitted torque, bending load, deflection, critical speed<\/div><\/li>\n <li><span class=\"feature-bullet\">\u25b8<\/span><div><strong>Typical materials:<\/strong> carbon steel, alloy steel, stainless steel<\/div><\/li>\n<\/ul>\n\n<h3>Rotary shaft use cases<\/h3>\n\n<div class=\"usecase-grid\">\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Conveyor systems<\/div>\n <div class=\"usecase-card-desc\">Drive shafts transmitting motor torque to conveyor rollers via sprockets and chain in a warehouse sortation system<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Packaging machinery<\/div>\n <div class=\"usecase-card-desc\">Timing shaft distributing synchronized rotation to multiple stations in a form-fill-seal machine via timing pulleys<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Automotive<\/div>\n <div class=\"usecase-card-desc\">Driveshafts and prop shafts transmitting engine torque to the wheels; cam shafts controlling valve timing<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Robotics<\/div>\n <div class=\"usecase-card-desc\">Output shafts of servo gearboxes transmitting high-torque, low-speed rotation to robot joint links<\/div>\n <\/div>\n <div class=\"usecase-card\">\n <div class=\"usecase-card-industry\">Industrial mixing<\/div>\n <div class=\"usecase-card-desc\">Agitator shafts driven by a motor through a gearbox, transmitting torque to impeller blades in a mixing vessel<\/div>\n <\/div>\n<\/div>\n\n<div class=\"cta-strip\">\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0800000000\/M0801000000\/M0801010000\/\" target=\"_blank\" rel=\"noopener\">Browse MISUMI rotary shafts<\/a>\n <a class=\"cta-btn cta-btn-outline\" href=\"https:\/\/blog.misumiusa.com\/sizing-timing-belts-and-pulleys\/\" target=\"_blank\" rel=\"noopener\">Sizing timing belts & pulleys \u2192<\/a>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"comparison\">Side-by-side comparison<\/h2>\n\n<table class=\"spec-table\" aria-label=\"Linear shaft vs post vs rotary shaft comparison\">\n <thead>\n <tr>\n <th class=\"prop-col\">Property<\/th>\n <th class=\"data-col\">Linear Shaft<\/th>\n <th class=\"data-col\">Post \/ Standoff<\/th>\n <th class=\"data-col\">Rotary Shaft<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td class=\"prop-col\">Primary function<\/td>\n <td class=\"data-col\">Guide sliding motion<\/td>\n <td class=\"data-col\">Position \/ space components<\/td>\n <td class=\"data-col\">Transmit torque & power<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Motion type<\/td>\n <td class=\"data-col\">Linear (translating)<\/td>\n <td class=\"data-col\">None (or fixed-axis pivot)<\/td>\n <td class=\"data-col\">Rotary<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Active or passive<\/td>\n <td class=\"data-col\">Passive<\/td>\n <td class=\"data-col\">Passive<\/td>\n <td class=\"data-col\">Active<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Rotates?<\/td>\n <td class=\"data-col\">No<\/td>\n <td class=\"data-col\">No (component rotates around it)<\/td>\n <td class=\"data-col\">Yes<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Transmits power?<\/td>\n <td class=\"data-col\">No<\/td>\n <td class=\"data-col\">No<\/td>\n <td class=\"data-col\">Yes<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Sizing driver<\/td>\n <td class=\"data-col\">Load, deflection, precision<\/td>\n <td class=\"data-col\">Required spacing, compressive\/bending load<\/td>\n <td class=\"data-col\">Torque, bending load, critical speed<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Typical cross-section<\/td>\n <td class=\"data-col\">Round (precision ground)<\/td>\n <td class=\"data-col\">Round, hex, or square<\/td>\n <td class=\"data-col\">Round (with keyway or spline)<\/td>\n <\/tr>\n <tr>\n <td class=\"prop-col\">Common mating parts<\/td>\n <td class=\"data-col\">Linear bushings, shaft supports<\/td>\n <td class=\"data-col\">Brackets, bearings, spacers<\/td>\n <td class=\"data-col\">Couplings, pulleys, gears, bearings<\/td>\n <\/tr>\n <\/tbody>\n<\/table>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"how-to-choose\">How to choose: define your motion first<\/h2>\n\n<p>As with a lot of engineering problems, identifying the type of motion is the most critical aspect of the design. Once you have that knowledge, choosing between linear shafts, posts, and rotary shafts is quite easy.<\/p>\n\n<div class=\"decision-grid\">\n <div class=\"decision-card\">\n <div class=\"decision-card-header\">Sliding or translating motion?<\/div>\n <div class=\"decision-card-body\">\n <strong>Use a linear shaft<\/strong>\n A carriage, tooling plate, or load needs to move in a straight line. An actuator provides the force; the linear shaft and bushing constrain and guide the path. Size by load and required precision.\n <\/div>\n <\/div>\n <div class=\"decision-card\">\n <div class=\"decision-card-header\">Transmitting power or torque?<\/div>\n <div class=\"decision-card-body\">\n <strong>Use a rotary shaft<\/strong>\n A motor needs to drive a load over a distance, or you need to change the speed or direction of rotation via belts, gears, or chains. Size by torque, bending load, and operating speed.\n <\/div>\n <\/div>\n <div class=\"decision-card\">\n <div class=\"decision-card-header\">Positioning, spacing, or pivoting?<\/div>\n <div class=\"decision-card-body\">\n <strong>Use a post<\/strong>\n You need to mount a component at a fixed height, separate two structural members, or create a fixed pivot point around which something rotates (like an idler pulley). Size by spacing requirement and load.\n <\/div>\n <\/div>\n<\/div>\n\n<div class=\"callout callout-note\">\n <strong>Mixed motion:<\/strong> Some applications combine motion types. A Z-axis stage may use linear shafts for the vertical slide and a rotary shaft driven by a motor via a belt to provide the drive force. In these cases, identify each motion independently and select the appropriate component for each function.\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"sizing\">Sizing considerations by type<\/h2>\n\n<h3>Linear shaft sizing<\/h3>\n<p>Select diameter based on the applied load and the acceptable deflection over the unsupported shaft span. A longer unsupported span dramatically increases deflection for a given load\u2014doubling the span increases deflection by a factor of eight for a simply supported beam. For applications requiring higher precision, choose a tighter tolerance class (h5 or h6). MISUMI linear shafts can be configured in 1mm length increments with a range of end treatments at time of order.<\/p>\n\n<h3>Post sizing<\/h3>\n<p>Posts in compression are sized by the required height and the load they must carry without buckling. Posts subject to bending (e.g., a cantilevered bracket mounted to a post) require attention to bending stress at the base. Hex posts offer a practical advantage for installation: the flat surfaces allow wrench tightening without a separate fixture. Round and square posts are available where cross-section geometry is a design constraint.<\/p>\n\n<h3>Rotary shaft sizing<\/h3>\n<p>Shafts transmitting torque are sized using the torsional shear stress equation, with a safety factor applied for shock loads and fatigue. Bending from overhung pulleys, gears, or sprockets adds to the stress at critical sections. At high speeds, verify that the operating RPM is below the shaft’s critical speed to avoid resonance. Keyway cuts and cross-drilled holes are stress concentration points that reduce fatigue life and must be accounted for in the sizing calculation.<\/p>\n\n<div class=\"callout\">\n <strong>MISUMI configurable shafts:<\/strong> MISUMI linear shafts, circular posts, and hex posts are manufactured in our Ohio facility. All three are configurable in 1mm increments with expanded dimension ranges. <a href=\"https:\/\/us.misumi-ec.com\/product\/promotion\/category\/automation-product-expansion\/\" target=\"_blank\" rel=\"noopener\">See the full expanded configurable dimensions for MISUMI automation components.<\/a>\n<\/div>\n\n<div class=\"cta-strip\">\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0100000000\/M0101000000\/\" target=\"_blank\" rel=\"noopener\">Linear shafts<\/a>\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M1500000000\/M1509000000\/M1509010000\/\" target=\"_blank\" rel=\"noopener\">Posts & standoffs<\/a>\n <a class=\"cta-btn\" href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M0800000000\/M0801000000\/M0801010000\/\" target=\"_blank\" rel=\"noopener\">Rotary shafts<\/a>\n<\/div>\n\n<div class=\"post-footer\">\n <p class=\"post-footer-title\">Related resources<\/p>\n <p class=\"post-footer-note\">\n <a href=\"https:\/\/us.misumi-ec.com\/blog\/sliding-guides-part-1\/\">Sliding Guides Part 1<\/a> \u00b7\n <a href=\"https:\/\/blog.misumiusa.com\/sizing-timing-belts-and-pulleys\/\">Sizing Timing Belts and Pulleys<\/a> \u00b7\n <a href=\"https:\/\/blog.misumiusa.com\/frequently-asked-questions-faqs-of-linear-guides\/\">Linear Guide FAQs<\/a> \u00b7\n <a href=\"https:\/\/blog.misumiusa.com\/elastomer-jaw-couplings-not-all-are-created-equal-with-rw\/\">Elastomer Jaw Couplings<\/a> \u00b7\n <a href=\"https:\/\/us.misumi-ec.com\/vona2\/mech\/M1000000000\/M1002000000\/\">Pulleys & Belts at MISUMI<\/a>\n <\/p>\n<\/div>\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>Updated July 24, 2026. Linear Shafts vs. Posts vs. Rotary Shafts: Differences, Uses & Selection Guide | MISUMI Linear shafts, posts, and rotary shafts are all cylindrical components found in machine assemblies\u2014but they serve fundamentally different purposes. This guide explains how each works, what type of motion each supports, real-world use cases by industry, and a simple framework for selecting […]<\/p>\n","protected":false},"author":46,"featured_media":10030,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false},"categories":[1136],"tags":[146,147,148],"aioseo_notices":[],"gutentor_comment":2,"_links":{"self":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/548"}],"collection":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/users\/46"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/comments?post=548"}],"version-history":[{"count":4,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/548\/revisions"}],"predecessor-version":[{"id":17147,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/548\/revisions\/17147"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/media\/10030"}],"wp:attachment":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/media?parent=548"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/categories?post=548"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/tags?post=548"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}