Flanged Blind Bore Sleeve with Blind Bore Depth ±0.02mm, Groove Width and Depth ±0.02mm, and Bore to OD Concentricity 0.01mm

A blind bore sleeve locates a pin, sensor, magnet or spring and stops it at a defined depth. Unlike a through bore, the bottom must be flat, square to the axis and at the correct depth — and chips have nowhere to go. A bottom that is not flat gives a false depth reading; a corner radius the drawing does not call for holds the pin off the seat; a chip left at the bottom shows up as a 0.05 mm short assembly that nobody can explain.

The sequence is therefore: turn the body, cut the groove, then bore to depth with a flat-bottom tool, measure the depth at the centre and near the wall, and clean the bore before the part leaves the machine. Flanges are turned square to the bore so the sleeve seats in its housing, and the outside groove is cut to the seal call-out rather than to a nominal.

ISO 9001:2015 certified · SS304 / 316L / 303, brass C36000 · Bores capped on delivery · Exporting since 2008.

• Material: SS304 standard, SS316L for corrosion, SS303 for fine finish and free machining, brass C36000 for instrumentation, 17-4PH where strength is needed.
• Geometry: flanged or plain, single flange or double flange, blind or through bore, internal groove, cross hole, spanner flats, hex body, knurl band.
• Sealing: outside O-ring groove, face O-ring groove, bonded washer land, flat gasket face.
• Finish: passivation, electropolish, bead blast, black oxide, nickel plating, as-machined.
• Size: OD 5 mm to 100 mm, bore 2 mm to 90 mm, depth up to 200 mm, wall from 1 mm.
• Input: STEP, IGES, DXF, PDF, or a sample sleeve we measure and re-model.

A sleeve drawing shows what sits inside the bore — a magnet, a sensor, a spring seat — and that is often the most private detail of an instrument. We sign a mutual NDA before opening any file, in English or Chinese or on your own form, and return a countersigned copy before work starts. Only the project engineer, the lathe programmer and the cell supervisor can access the file, which sits in a restricted folder rather than the open shop network. No photographs of customer parts are taken for our catalogue or website, customer parts are never displayed or reused as samples, subcontracting requires your written approval, and at program close files and inspection data are deleted or returned with written confirmation.

Dongguan Changxinda Precision Technology Co., Ltd has been machining custom parts since 2008: 15+ years, 90 to 100 staff, 50–60% exported to North America and Europe, 200+ customers served, turnover in the RMB 10–20 million band. The floor holds CNC lathes, turn-mill combined centres with sub-spindle and live tooling, and 4-axis / 5-axis machining centres under an ISO 9001:2015 system, producing parts for medical, robotics, automotive, aerospace, automation, laser, LED, lithium battery and precision instrument programs. Turning, grooving, boring, passivation coordination and borescope inspection are all in our own plant in Dongguan.

Turned sleeves and housings from this plant ship into ten industries. Each line is a category we machine regularly, with the parts customers actually order.

All ten sectors run through the same plant and the same ISO 9001:2015 inspection discipline — only the material, finish and documentation package change.

• Prototype: 3–7 working days after drawing approval, including passivation.
• Small batch 10–100 pcs: 7–14 working days.
• Repeat orders: run from archived programs, collets and boring bars; blind depth and groove position repeat to the same values.
• Capacity: 10,000 pieces per month across the plant.
• Visibility: a dated progress note with photographs of your actual sleeves at turning, boring and inspection.
• Shipping: bores capped, parts bagged, foam-lined export carton, express or air and sea per your forwarder.
• Rush: overtime slots and an express passivation line held weekly; tell us the deadline and we confirm before you order.