About Carbon Steel, Alloy Steel, Spring Steel, and Cast Iron
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Selecting Compatible Lead Screws and Nuts
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Ball Splines and Bearings

Create a compact linear and rotary motion system for applications requiring complex, fast movements, such as robotics. The grooves on the ball splines transmit rotary power as ball bearings move smoothly and precisely along their length, even at high speeds.
Ball splines are alloy steel for high strength and wear resistance. They're hardened on the outside for additional wear resistance while the center is soft enough to absorb stress from shifting loads. Those with a step-down end have a shoulder near the end to stop gears, sprockets, and bearings.
Bearings have a retaining ring groove, so they can be positioned in your system with a retaining ring (not included). Bearings with a keyway include a machine key for attaching your load. Flanged bearings have a surface with mounting holes for attaching your load.



Spline | Step | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dia., mm | Dia. Tolerance, mm | Lg., mm | Lg. Tolerance, mm | Lg., mm | No. of | Root Dia., mm | Dia., mm | Dia. Tolerance, mm | Lg., mm | Surface Smoothness, microinch | Edge Type | Hardness Rating | Hardness | Heat Treatment | Each | |
Metric—52100 Alloy Steel | ||||||||||||||||
Splined End × Step-Down End | ||||||||||||||||
28 | -0.021 to 0 | 450 | -0.7874 to 0.7874 | 300 | 4 | 24.8 | 25 | -0.021 to 0 | 150 | 16 | Chamfered | Very Hard | Rockwell C60 | Case Hardened | 00000000 | 0000000 |

Material | Keyway | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Spline Dia., mm | For No. of Splines | Overall Lg., mm | OD, mm | Bearing | Ball | Dynamic Load Cap., lbs. | Max. Dynamic Torque, in.-lbs. | With Retaining Ring Grooves | Includes | Dp., mm | Lg., mm | Wd., mm | Each | |
28 | 4 | 80 | 45 | Steel | Steel | 4,150 | 2,557 | Yes | Machine Key | 4 | 41 | 7 | 00000000 | 0000000 |


Material | Mounting Hole | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Spline Dia., mm | For No. of Splines | Overall Lg., mm | Flange OD, mm | OD, mm | Bearing | Ball | Dynamic Load Cap., lbs. | Max. Dynamic Torque, in.-lbs. | With Retaining Ring Grooves | No. of | Thread Size | Each | |
28 | 4 | 80 | 70 | 45 | Steel | Steel | 4,150 | 2,557 | Yes | 4 | M6 × 1 mm | 00000000 | 0000000 |
Low-Carbon Steel Rods and Discs

- Yield Strength: See table
- Hardness: See table
- Heat Treatable: Yes
- Max. Hardness After Heat Treatment: See table
- Fabrication: See table
- Specifications Met: See table
Also known as mild steel, low-carbon steel is easy to machine, form, and weld. It's widely fabricated into low-strength fasteners, pins, and axles. You can surface harden this material for added wear resistance. All have been manufactured to meet ASTM standards for quality and performance.
Cold-worked rods and discs have a finished look and quality. The cold-working process gives the steel consistent strength, hardness, and dimensions throughout.
For technical drawings and 3-D models, click on a part number.
Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
Metric Lead Screws and Nuts

Found in hand-powered clamps, vises, grates, doors, and work tables, lead screws and nuts have broad, square threads that are well suited for quick assembly, high clamping forces, and lifting and lowering heavy objects. To ensure compatibility, please select components that have the same thread direction, size, pitch, and number of thread starts. Class 7e and 7H components are compatible.
932 bearing bronze components are more wear resistant than brass components. They have good machinability and fair corrosion resistance.
Travel distance per turn, also known as screw lead, is the distance a nut moves with one revolution of the lead screw.
For technical drawings and 3-D models, click on a part number.

Flange nuts move objects along the length of a lead screw. They have a wide machinable flange for custom mounting.