Stainless Steel Ball Screw Shaft and Nut Assembly

This is a custom ball screw shaft and nut assembly machined from stainless or alloy steel for linear motion systems, e-bike drives and motorcycle actuators. We turn the shaft, mill end journals and keyways, and machine nut bodies and flanges to the customer's drawing. It is intended for engineers who need non-standard lengths, end machining or matched nuts.

Material: Stainless Steel
Tolerance: to ±0.005 mm
MOQ: 1 piece
Prototype lead time: 3–7 days

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Custom journals, keyways and threads on screw ends
304, 316, 17-4PH stainless or 4140 alloy steel
Runout to screw axis checked before shipment
Matched nut bodies and flanges machined to drawing

ISO 9001 quality system, 100% critical-dimension inspection

NDA on request; your drawings are never shared

Door-to-door shipping with export documents

Item ref. 1601681769454 ·

Specifications
Process	CNC turning with tailstock, CNC milling of flanges and keyways
Materials	Stainless steel 304, 316, 17-4PH; alloy steel 4140
Tolerance	±0.05 mm standard; down to ±0.005 mm on critical features
Surface Finish	Passivation, black oxide, heat treatment on request
Critical Features	Journal diameters, runout, thread pitch
MOQ	1 piece; prototypes through mid-volume
Drawing Formats	STEP, IGES, X_T, STL, DWG, DXF, PDF
Lead Time	Prototypes typically 3–7 working days; production 10–20
Inspection	First-article, in-process and CMM checks; reports on request

Manufacturing

How we make this part

Process, material options and inspection for stainless steel ball screw shaft and nut assembly.

Ball screws are mostly about the ends. Most buyers need a shaft with custom journals, bearing seats, threads and keyways that fit their own housings, so we turn those features concentric to the screw axis on CNC lathes with tailstock support. Long slender shafts are machined in stages to control deflection, and the nut flange, mounting holes and wiper grooves are milled after turning.

For corrosive or washdown environments, 304 or 316 stainless steel avoids rust but is softer than hardened alloy steel, so load and life ratings are lower. 4140 alloy steel can be heat treated for higher hardness and wear resistance, then black oxide coated for mild protection. 17-4PH stainless offers a middle path: precipitation hardened for strength while remaining corrosion resistant.

Journal diameters, runout relative to the screw axis and thread pitch are checked before shipment, using CMM and thread gauges for critical features. Material certificates can be supplied for stainless and alloy grades. Typical uses include linear actuators on automation stages, e-bike and motorcycle seat or suspension adjusters, small CNC machine axes and medical positioning tables.

FAQ

Frequently asked questions

Can you machine the ends of a ball screw I already have?

Yes. If you supply rolled or ground screw stock, we can machine custom journals, bearing seats, threads and keyways to your drawing. Hardened screw sections may need annealed ends or a different approach, so tell us the screw grade and hardness when you request a quote.

Is stainless steel suitable for a load-bearing ball screw?

It works for light to moderate loads and corrosive environments, but standard 304 or 316 is softer than hardened bearing steel, so wear life is shorter. For higher loads, 17-4PH stainless or heat-treated 4140 alloy steel is a better choice. We can help compare options against your load data.

How do I get a quote for stainless steel ball screw shaft and nut assembly?

Send a 3D model (STEP or IGES) and a 2D drawing with tolerances, material, finish and quantity through the quote form or by email. An engineer replies within 24 hours on business days with price, lead time and any DFM suggestions.