Long Nut Machining
CNC turning, boring, heat-treatment allowance, and final internal thread grinding are planned as one route to protect concentricity.
The hardest process in inverted roller screw manufacturing is the long internally threaded nut. We focus this page on lead accuracy, profile control, surface finish, runout, and the inspection evidence buyers need before trusting a custom supplier.
Inverted roller screws depend on a long nut with an accurate internal thread over the working stroke. The manufacturing review checks whether the proposed nut length, wall thickness, heat treatment, and grinding access can be controlled before sample machining begins.
CNC turning, boring, heat-treatment allowance, and final internal thread grinding are planned as one route to protect concentricity.
Nut, screw shaft, rollers, and timing rings are reviewed as a matched assembly when preload and smooth torque matter.
First-article data, CTQ dimensions, and drawing revision are frozen before moving from prototype to small batch.
| Control Point | Typical Evidence | Why It Matters |
|---|---|---|
| Lead Accuracy | Laser or profile inspection over the working stroke. | Prevents positioning error and uneven roller load sharing. |
| Surface Roughness | Ra/Rz report on ground internal thread surfaces. | Reduces friction, heat, and premature wear in compact actuators. |
| Runout & Coaxiality | CMM or dedicated fixture report for nut datum features. | Protects against misalignment during motor or push-tube integration. |
| Lot Traceability | Material certificate, heat number, hardness, and CoC package. | Gives procurement a stable record for sample approval and repeat orders. |
| Stage | Control Point | Buyer Output |
|---|---|---|
| DFM review | Confirm nut length, thread access, datum scheme, material, hardening, and inspection targets. | Manufacturing notes and open questions before quote freeze. |
| Pre-grind machining | Control straightness, bore allowance, heat-treatment distortion, and datum consistency. | First-article checkpoint before precision grinding. |
| Internal grinding | Manage pitch deviation, flank angle, roughness, coaxiality, and grinding burn risk. | Lead/profile/roughness report tied to drawing revision. |
| Assembly validation | Verify smooth torque, axial play or preload, runout, and lubricant plan with the screw and rollers installed. | Sample release evidence for buyer-side actuator testing. |
Send drawings to [email protected] or WhatsApp +86 18857971991 for a manufacturing review.
Inquiry Email
Include target OD, lead, stroke, load, quantity, and delivery country.
WhatsApp Engineering
+8618857971991
Best for quick RFQ clarification and drawing-review coordination.