Description

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Precision Threaded Shafts combine tight-tolerance journal/bearing diameters with rolled, cut, or whirled thread profiles. Engineered for axial translation, multi-point load transfer, or fine mechanical adjustment.

Diameter Range: Dia 4 mm to dia 80 mm.

Max Length: Up to 1,500 mm (slender-ratio controlled via steady-rest turning).

Thread Forms: Metric (ISO), Unified (UNC/UNF), Trapezoidal (Metric ACME), Stub ACME, or custom root/crest profiles.

Technical Specifications

Parameter	Specification Scope	Standard / Verification Method
Base Materials	AISI 4140, 303/304/316 Stainless, 17-4PH, C45E, 42CrMo4	MTRs / Material Test Reports (EN 10204 3.1)
Dimensional Tolerance	ISO h6 / h7 on journals; 6g/6h or custom pitch fits	Micrometer / Plug & Ring Gauges
Straightness (TIR)	<= 0.03 mm / 300 mm (tighter on request via stress relief)	Dial Indicator on V-blocks
Concentricity (TIR)	<= 0.015 mm (journal datum to thread pitch cylinder)	Optical CMM / Rotary Indexer
Hardness Options	Annealed (HB 180-220), Through-hardened (HRC 28-32), Induction hardened (HRC 55-60, depth 0.5-1.2 mm)	Leeb / Rockwell Hardness Tester
Surface Finish	Ra <= 0.4 um (journals), Ra <= 1.6 um (thread flanks)	Surface Roughness Tester

Key Features

Thread Processing Method Matched to Geometry: Thread rolling for high fatigue strength and grain flow preservation (up to M36); single-point CNC thread turning or whirling for custom multi-start or large-pitch profiles.

Controlled Stress-Relief Cycle: Intermediate thermal stress-relieving performed between rough turning and finish grinding/rolling to eliminate post-machining thermal drift.

Burr-Free Root Geometry: Chamfered thread starts and deburred flanks; inspected under 10x magnification for optical automation compatibility.

Datum-Consistent Manufacturing: Turning, threading, and cylindrical grinding executed against unified primary/secondary locating datums to hold TIR limits.

Applications

Medical Infusion & Diagnostic Pumps: Stainless 316/17-4PH precision lead/threaded shafts for micro-displacement fluid dosing.

Industrial Automation Z-Axis Stages: Heat-treated 4140 threaded shafts paired with anti-backlash nuts for vertical positioning.

Optical & Laser Alignment Mounts: Fine-pitch metric/imperial adjustment screws with controlled frictional torque.

Robotic Joint Retainers & Actuators: High-torsion load-bearing threaded spindles.

Customization & Engineering DFM Support

Modifications: Cross-drilled holes, keyways, flat millings, snap-ring grooves, proprietary grease grooves, anti-corrosion passivation, black oxide, or hard chrome plating.

Batch Flexibility: Prototype runs (>= 25 pcs) with full PPAP/FAI documentation; scheduled blanket orders with Kanban release.

Compliance & Reporting: Full PPAP Level 3 and IMDS reporting available upon request (EU/German automotive & medical tier-2 aligned).

Standard Lead Time:
• Prototype FAI: 10-15 business days
• Production batch (500-2,000 pcs): 3-4 weeks

Quality Control Workflow

100% Inspection Items: Thread GO/NO-GO gauge check, major/minor diameter micrometer audit.

Sampling / Batch Verification:
CMM concentricity & cylindricity map (ISO 2859-1 Level II, AQL 1.0).
Optical profile projection for thread angle (60 deg / 30 deg flank angle verification).
Cross-section hardness depth check on destruct-coupon or batch witness piece.

Traceability: Laser-etched heat number / batch code on non-critical shaft shoulder mapped to digital MTR archives.

Manufacturing Footprint & Process Control

Machining Assets: 18 CNC turning centers (with live tooling), 4 high-precision cylindrical grinders, 2 thread-rolling machines.

Process Flow: Raw material MTR chemical verification -> Sawing/Billet prep -> Rough CNC turning -> Stress relief anneal -> Semi-finish turning -> Induction hardening/quenching (if specified) -> Cylindrical/Thread finish -> Ultrasonic clean -> 100% QC.

Certifications: ISO 9001:2015 certified. Process parameters locked per part number under PFMEA / Control Plan governance.

Packaging & Delivery

Individual Protection: Each shaft wrapped in VCI (Volatile Corrosion Inhibitor) film, inserted into sealed heavy-wall PVC protective tubes.

Bulk Packaging: Multi-layer EPE foam slotted separator trays inside double-wall export corrugated cartons (max 15 kg/box) or fumigation-free plywood crates for palleted orders, complete with humidity indicator cards and desiccant bags.

Logistics Options: FOB, CIF, or DDP via air/sea freight. ITAR-conscious supply chain mapping available for US/EU defense-adjacent commercial sub-assemblies.

FAQ

Q: Can you prevent straightness warping on long slender shafts (L/D > 25) after heat treatment?

A: Yes. We apply fixture-restrained induction hardening or low-temp vacuum heat treatment followed by mechanical micro-straightening press check to maintain TIR <= 0.05 mm over 500 mm.

Q: What is your standard lead error control for rolled threads?

A: Rolled threads typically hold ISO lead accuracy grade 7 (or grade 5/6 via precision die matching). Specify your cumulative pitch tolerance window on the drawing for verification.

Q: Do you supply MTRs and heat-treatment certs with shipment?

A: Yes. EN 10204 3.1 MTRs and certified heat-treatment hardness/depth test reports ship digitally prior to dispatch and physically with the crate.

Q: What is the minimum order quantity (MOQ) for custom thread pitches?

A: Non-standard pitch rolling dies require setup fee; economic batch starts at 50-100 pcs depending on OD diameter. Single-point turned custom pitch accepts prototype quantities from 10 pcs.

Request a Quote (RFQ)

Submission Checklist:
CAD file (.STEP) & PDF drawing with toleranced critical datums.
Material grade & heat-treatment requirement / MTR preference (EN 10204 3.1).
Annual volume / release schedule / PPAP Level 3 requirement.
Target delivery port / destination postal code for DDP quote.

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