What are Unthreaded Rods?
Unthreaded rods are smooth round bars used for shafts, axles, pins, spacers, guides, and general fabrication. They are easy to cut and machine, and they come in many materials and lengths to fit shop or field work.
What are unthreaded rods used for?
- Shafts, axles, and guide rods
- Spacers, standoffs, and posts
- Linkages, hinges, clevis pins, and pivots
- Fixtures, frames, and supports
How to choose diameter, material, and finish
- Diameter: match bearing or bushing size, required load, and desired fit. Leave machining allowance if you will turn, grind, or finish the surface.
- Material options: carbon steel for general use, alloy or precision shafting for tighter tolerances, 304 stainless for broad corrosion resistance, 316 stainless for chloride or marine areas, aluminum for low weight, brass or bronze for machinability and non-sparking needs.
- Finish and tolerance: standard mill round bar suits general fabrication. For smooth sliding or linear bearings, choose turned-ground-polished or h6 precision shafting.
- Length: common sticks are 3 ft, 6 ft, and 10–12 ft, with cut-to-length as needed.
Can you cut and thread unthreaded rod?
Yes. Cut with a saw or cutoff wheel, deburr the ends, and, if threads are required, use a die or lathe to cut threads. Chase or chamfer the start so nuts engage cleanly. For corrosion-exposed threads consider stainless or a protective coating after machining.
We offer custom cutting services! Visit our Custom Cutting Services page for more information.
Can I drill, tap, or cross-pin round bar?
Yes. Round bar machines well. Mark and center-drill to prevent walking, use proper fixturing, and deburr. For cross-pins, spot both sides for alignment. Use cutting fluid appropriate to the material.
Straightness, surface finish, and tolerance
- General round bar: suitable for supports and spacers where basic straightness is acceptable.
- Precision shafting: tighter straightness and surface finish for bearings and linear motion. Look for ground finishes and h6 diameter tolerance when smooth travel or accurate fit is needed.
Installation & best practices
- Measure the mating hole, bushing, or bearing, then select a diameter and tolerance that achieve the desired clearance or press fit.
- Cut to length, square the ends, and deburr. Add a small chamfer for safe handling and easier assembly.
- For sliding applications, keep surfaces clean, align components, and verify smooth travel before final tightening.
- Apply suitable protection for the environment, for example stainless or coated steel in wet areas.
Troubleshooting & tips
- Rod binds in bushings: misalignment or rough finish. Check parallelism, polish, or use precision shafting.
- Corrosion in service: select 316 stainless or a more protective finish for the environment.
- Ends mushroom after cutting: deburr and chamfer, verify square cuts, and avoid over-tight press fits.
- Noticeable wobble: check straightness. Use turned-ground-polished or h6 shafting where runout matters.
Why buy Unthreaded Rods from AlbanyCountyFasteners.com
- Round bar for general fabrication and shafting needs
- Popular diameters, materials, and practical stick lengths
- Cut-to-length options with fast shipping
- USA-based support for sizing, tolerances, and machining questions
Unthreaded Rods FAQs
Concise answers to help you size, machine, and finish unthreaded rods.
What material should I choose for a shaft or guide rod?
Pick precision shafting or ground stainless for smooth travel. Use 316 stainless in chloride or marine areas, 304 in many general environments, carbon steel for dry indoor fabrication, and aluminum when weight matters.
What tolerance should I look for with linear bearings?
Use ground shafting with tight straightness and diameter control, commonly ISO h6 for linear bearings and bushings.
What lengths are available?
Common sticks are 3 ft, 6 ft, and 10–12 ft. Cut-to-length is often available; leave extra for facing and chamfering.
Can I tap threads in round bar?
Yes. Drill the correct tap size, use cutting fluid, and deburr. For external threads, use a die or turn on a lathe, then chamfer the start for easy nut engagement.
How do I prevent rust on carbon steel round bar?
Use coatings, paint, or choose stainless. For coastal exposure, step up to 316 stainless.
What is the difference between unthreaded rod and threaded rod?
Unthreaded rod is smooth bar stock for machining or press/slide fits. Threaded rod is fully threaded bar used with nuts and washers for hangers and assemblies.