Clamp Style Stainless Steel Coupling Adapter Sleeve Turned 0.008mm Bore Concentricity for Encoder Drive Assembly

Company Introduction

Dongguan Changxinda Precision Technology Co., Ltd is a custom machining manufacturer founded in 2008 in Dongguan, China. We run four-axis and five-axis machining centres, turn-mill combined lathes, CNC lathes and milling machines, employ 90 to 102 people and operate an ISO 9001:2015 quality system. More than 200 customers have been served, 50 to 60 percent of output is exported, and annual sales are between USD 10 million and 20 million. Our engineers work from customer drawings rather than a fixed product list, which is why a clamp style sleeve with a keyway and a balance requirement is routine work for us.

Product Description

This clamp style coupling adapter sleeve holds the shaft with a split collar instead of a set screw. The clamp screw closes a controlled gap, so the bore grips the shaft evenly around its circumference and leaves no dimple, burr or scored journal behind. That matters on hardened servo shafts, hollow encoder shafts and any assembly that has to come apart for service without a replacement shaft. The sleeve is turned from stainless steel, with the clamping bore and the pilot bore machined in one clamping to hold 0.008 mm concentricity.

The body can carry a keyway for positive torque transmission, a shoulder for axial location, and a chamfered lead-in so the shaft enters without catching the clamp gap. For high-speed encoder and robotics drives, the finished part can be dynamically balanced to G6.3 at 8,000 rpm and shipped with a balance report.

Manufacturing Process

1. Drawing review and process plan. We check clamp gap, screw size, keyway width, wall thickness under the clamp and the balance requirement, then issue a process plan and quotation within one working day.
2. Material check. Stainless bar is verified for grade and condition against the mill certificate; 17-4PH is confirmed for heat-treat condition.
3. Cutting and stress relief. Blanks are cut oversize and stress relieved so the clamp gap does not close or spring after the collar is slit.
4. Turning of bores and body. The clamping bore, pilot bore, shoulder and outside diameter are turned in one programme; the bore is left with reaming allowance and finished to H7.
5. Collar slitting. The split is cut with a fine slitting saw or wire EDM to a controlled gap, then deburred so the clamp screw seats flat.
6. Keyway and screw holes. The keyway is broached or milled to width +/-0.02 mm, and the clamp screw hole is drilled and tapped square to the split face.
7. Passivation and finishing. Parts are passivated after machining; glass bead blasting or electropolishing is available when a specific surface appearance is required.
8. Inspection and packing. Air gauge for bore size, runout fixture for 0.008 mm TIR, CMM sampling, balance check when specified, then individual bagging with foam protection.

Precision Data

Clamp Design and Shaft Protection

A set screw transmits torque through a single point and leaves a permanent mark on the shaft; a split collar distributes the load around the full bore and releases cleanly when the screw is backed off. We hold the gap width to a controlled value so the collar does not bottom out before it grips, and we check the screw thread depth so the screw cannot protrude into the bore and score the shaft. Where the application reverses direction, we recommend a keyway in addition to the clamp, and we machine both features in the same setup so the keyway and the clamp axis stay aligned.

Custom Manufacturing

Every dimension here can be changed: bore combination, outside diameter, length, clamp screw size and position, keyway width, shoulder position, material grade, heat treatment, passivation and balancing. A single unit is enough to start, with no tooling charge and no setup fee, and the prototype is produced with the same fixture and inspection plan as the batch. If a drawing feature would add cost without adding function, our engineer returns a DFM note with a practical alternative and waits for written approval before production begins.

Confidentiality and Data Control

• NDA before drawings. A mutual non-disclosure agreement is signed before models, drawings or samples are released, covering geometry, volume, end use and customer identity.
• No public reference. Confidential sleeves are never used as samples, catalogue items, website photos or trade show displays; photos require written release.
• Dedicated cell. Sensitive projects run in a segregated area with named operators, and programmes and fixtures are stored under a project code rather than a customer name.
• Controlled supply chain. Passivation and heat treatment partners receive the process specification only, never the assembly drawing or end use.
• Traceability kept internal. Batch records are retained for three years so a quality question can be answered without exposing the design to a third party.

Stable Delivery

• Fixed slots for repeat parts. Blanket and repeat orders are booked into reserved machine time, so the same part arrives in the same week each month.
• Confirmed dates. Prototypes in 5 to 8 working days, batch orders in 12 to 22 working days after drawing approval, with the date written into the order confirmation.
• No re-programming on repeat orders. Programmes, fixtures and inspection plans stay on file, removing setup time from the second order onward.
• Early risk notice. If material, slitting, passivation or balancing threatens the date, you hear it before the date is missed, with a partial shipment or air-freight option.
• Dispatch evidence. Photos, inspection report and packing list before shipment; tracking number on the day of dispatch.

Ten Industries We Machine For

• ✅ Consumer Electronics: phone, tablet and laptop housings, heat sinks, camera brackets, VR/AR headset structural parts, smart wearable shells
• ✅ Automation & Industrial Equipment: automation fixtures, jigs, module frames, transmission sliders, motor mounts, sensor housings, conveyor line parts
• ✅ Semiconductor & Vacuum Equipment: vacuum chambers, vacuum fittings, precision equipment bases, thermal isolation and insulation parts, inspection fixtures
• ✅ Medical Devices: surgical instrument bases, diagnostic instrument housings, endoscope components, aesthetic device structural parts (medical-grade aluminum and stainless steel)
• ✅ Automotive: new energy motor housings, battery end plates, sensor brackets, lamp structural parts, tuning parts, hydraulic valve blocks
• ✅ Aerospace & UAV: aircraft structural parts, drone frames, landing gear parts, avionics instrument housings (lightweight precision parts)
• ✅ Optics & Photonics: optical lens barrels, lens mounts, light source heat sinks, camera module brackets, inspection optical benches
• ✅ Communications: 5G heat dissipation cavities, filter parts, signal adapter structural parts, telecom equipment housings
• ✅ Robotics: robot arm joint parts, robot bases, reducer housings, AGV structural parts
• ✅ Instrumentation: test equipment housings, precision gauge bases, flow meter parts, laboratory equipment accessories

Packing for Export

Each sleeve is packed in a bubble bag, seated in a custom EPE cavity tray so polished bores and clamp faces cannot rub, then sealed in a moisture barrier bag with desiccant. The tray fits a five-layer export carton printed with part number, quantity and batch code. Sea freight ships on fumigation-free plywood pallets with strapping and stretch film; neutral cartons are available for customers selling under their own brand.

FAQ

Q: How does a clamp style sleeve compare with a set screw sleeve?
A: The clamp spreads the grip around the bore and leaves the shaft undamaged, so the assembly can be serviced and re-used. A set screw is cheaper and shorter, but it marks the shaft and concentrates torque at one point.

Q: Can you hold 0.008 mm concentricity on a split part?
A: Yes. The bores are turned before the collar is slit, the split is cut with a controlled gap, and the finished part is checked on a runout fixture. The clamp screw is torqued to the specified value during inspection.

Q: Do you sign an NDA and keep the part off your website?
A: Yes. The NDA is signed before files are released, and confidential parts are excluded from samples, photos and case studies by default.

Q: Can you add a keyway and balance the part?
A: Yes. Keyways are cut to DIN 6885 or a custom width, and dynamic balancing to G6.3 at 8,000 rpm is available with a report.

Q: What is the minimum order?
A: One piece, with no tooling charge and no setup fee.

Send the drawing with bore sizes, clamp screw position and the maximum running speed, and we will reply with a DFM review, a quotation and a confirmed delivery date within one working day.