0.008mm Bore Roundness QBH Connector Locking Sleeve in 304 Stainless Steel CNC Turned for Laser Delivery

Send Drawing · NDA Available · Price in 24h — 0.008 mm bore roundness · 0.01 mm bore to OD · polished fiber passage

This is the locking sleeve inside a QBH fiber connector. The connector latches onto a laser head, the ferrule sits in the bore, and the sleeve holds that ferrule concentric with the optical axis while the latch takes the pull. Two numbers decide whether the connection works: how round the bore is, and how well the bore lines up with the outside diameter that centres the sleeve in the housing.

A bore that is 0.02 mm out of round clamps the ferrule at two points and leaves a gap at the third, so the fiber tip sits at a slight angle. At 1 kW that angle turns into a measurable loss and, worse, into heat at the connector face. We turn the bore to 0.008 mm roundness, hold taper to 0.005 mm over the length, and keep bore to OD concentricity at 0.01 mm.

1. Drawing and fit review. We check bore diameter and tolerance, ferrule clearance, groove position, keyway width and the latch interface, then quote within one working day.
2. Bar stock verification. 304 or 316L bar is checked against the mill certificate for grade and condition. For fiber connectors we normally use 304 for machinability and 316L where corrosion resistance matters more.
3. Saw, face and centre. Bars are sawn oversize, faced square and centred so the first turning pass runs true to the bar axis rather than to the saw cut.
4. Rough turning. OD and bore are roughed with 0.3 mm stock left, which keeps the finishing pass cool and prevents the thin wall from springing.
5. Bore drilling and boring. The bore is drilled undersize, bored to bring it on centre, then reamed or fine-bored depending on the diameter and finish specified.
6. Finish turning in a collet. The OD is finished in a collet rather than a three-jaw chuck, because jaw pressure on a thin sleeve closes the bore into a three-lobed shape that no reamer will correct.
7. Groove, keyway and chamfers. The snap-ring groove is cut with a form tool to ±0.02 mm width and depth; the keyway and anti-rotation flats are milled with live tooling in the same setup, so the keyway is clocked to the groove.
8. Passivation and inspection. Parts are passivated, then air-gauged for bore size, checked for roundness at three depths, CMM’d for concentricity and groove position, bore-scoped for tool marks, and released with a first article report.

Buyers often specify a bore diameter with a tight tolerance and stop there. Diameter tells you whether the ferrule fits; roundness tells you whether it sits straight. A bore can measure exactly on nominal with a two-point micrometer and still be triangular from chuck pressure, which is why we finish the OD in a collet and inspect the bore with a three-point air gauge at three depths rather than with a plug gauge alone.

Groove and keyway are cut after the bore is finished, in the same clamping where possible, because a second operation re-chucks the part on a surface that has already been machined and adds a new error. For a sleeve with a 1.2 mm wall, that error shows up immediately as a bore that is no longer round.

Bore diameter, wall thickness, groove profile, keyway size, flat positions, thread type, material grade and surface finish are all built to your drawing. One piece is a normal order with no tooling charge and no setup fee, and the prototype is turned on the same machines and inspected to the same plan as a batch. If a wall is too thin for the groove depth you specified, our engineer raises it in a DFM note before the bar is cut.

• NDA before files. Mutual non-disclosure is signed before drawings or samples are released, covering geometry, volume, end use and customer identity.
• No public reference. Confidential sleeves never appear as samples, catalogue items, website photos or trade show parts.
• Separated cell. Sensitive work runs with named operators and project-coded programmes.
• Partner control. Passivation and polishing suppliers receive process specifications only.

Dongguan Changxinda Precision Technology Co., Ltd has turned and milled custom parts since 2008. The plant runs CNC lathes with live tooling, turn-mill centres, four-axis and five-axis machining centres, employs 90 to 102 people under ISO 9001:2015, serves more than 200 customers, exports 50 to 60 percent of output and records annual sales of USD 10 to 20 million.

• Dates in writing. Prototypes 4 to 7 working days, batch orders 12 to 20 working days after drawing approval.
• Repeat orders skip setup. Programmes, collets and gauge sets stay on file.
• Bar stock on hand. Common 304 and 316L diameters are stocked, so a repeat does not wait for material.
• Early notice. If material, passivation or capacity threatens the date, you are told before the date is missed.
• Dispatch evidence. Photos, inspection report and packing list before shipment.

• ✓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

Each sleeve is bagged with desiccant, seated in a foam tray so the bore and groove cannot be bruised, and packed in a five-layer export carton marked with part number, quantity and batch code. Sea freight ships on fumigation-free plywood pallets; neutral cartons are available.

Send the drawing with bore tolerance, groove position and keyway width, and we will reply with a DFM review, a quotation and a confirmed delivery date within one working day.