Straight Knurled Bushing and Knurled Sleeve in Stainless Steel with 0.01mm Bore Tolerance for CNC Turning

A knurled bushing is a fit-and-grip component: the bore carries the shaft or pin at a controlled clearance, and the knurl on the outside either holds the part in a moulded plastic or aluminium housing without rotating, or gives an operator something to grip while turning. Both jobs live or die on two numbers — the bore size and the concentricity between bore and knurl crest circle — so we machine the bore and the knurl diameter from the same chucking and inspect them against the same datum.

These parts are turned from solid bar on CNC lathes and turn-mill centres, not bought in and reworked. Outside diameter, knurl band length, bore, counterbore, chamfers, groove and overall length are all set by your drawing, and both ends are faced square to the bore so the sleeve seats flat in a press or a bore.

Where your drawing is tighter on the bore and looser on the knurl, we work to your drawing rather than forcing the whole part into our default band — that keeps the cost on the feature that actually matters.

• Input: STEP, IGES, DXF, PDF drawing, or a worn sample we measure and model first.
• Knurl options: straight knurl, diamond knurl, spiral knurl, coarse or fine pitch, partial knurl band, knurl with relief groove, knurl plus hex or flats for a wrench.
• Bore options: through bore, blind bore, stepped bore, counterbore, internal groove, keyway, cross hole, threaded bore, PTFE-lined bore on request.
• Outside features: flange, shoulder, collar, O-ring groove, external thread, chamfer or radius on knurl ends.
• Materials: SS303 (free machining, best for fine knurl), SS304, SS316/316L, SS416, 17-4PH, brass C36000, 6061 or 7075 aluminium.
• Size range: 4 mm to 120 mm outside diameter, 10 mm to 300 mm length, wall down to 1 mm.
• Marking: laser part number, batch code or customer logo on the end face, so incoming inspection can match the delivery note.

Bushing drawings often carry a customer bore fit, a proprietary knurl band and a part number that identifies a product line. Before we open any file we sign a mutual NDA — ours in English or Chinese, or yours if you prefer. Inside the plant the file is visible only to the project engineer, the lathe programmer and the cell supervisor; the file sits in a restricted folder, not on the general shop network. No photographs of your part are taken for our catalogue or website, and customer parts are not left on display or used as samples for other enquiries. Subcontracting is not allowed without your written approval. On request we machine your part in a separated time slot, and at program close we delete or return the drawings and inspection data with written confirmation.

Dongguan Changxinda Precision Technology Co., Ltd has machined custom metal parts since 2008 — 15+ years, 90 to 100 staff, 50–60% of output exported to North America and Europe. The plant runs CNC lathes, turn-mill combined centres and 4-axis / 5-axis machining centres under an ISO 9001:2015 quality system, serving medical equipment, robotics, automotive, aerospace, automation, laser, LED, lithium battery and precision instrument customers, with more than 200 customers served and annual turnover in the RMB 10–20 million band. Turning, milling, knurling, grinding and inspection happen in our own plant in Dongguan, so your schedule is not exposed to a third party.

• Prototype: 3–7 working days after drawing approval, including knurl sample approval if a new pitch is involved.
• Small batch 10–100 pcs: 7–14 working days, planned into a reserved turning cell slot.
• Repeat orders: released directly from the archived program, knurl wheels and fixture — lead time does not restart from zero.
• Capacity: 10,000 pieces per month across the plant.
• Visibility: a dated progress note with photos of the actual parts at turning, knurling and inspection stages.
• Shipping: individual bag plus export carton with foam, express (DHL / FedEx / UPS) or air and sea per your forwarder, customs documents prepared.
• Rush: weekly overtime slots held for line-down or urgent prototype work — give us the required date and we confirm before you order.

Attach the model or drawing, tell us the quantity and the date you need the parts, and you will get a quotation, a process route and a firm delivery date — not a list of questions you have already answered. Prototype and NDA paperwork can be handled in the same exchange.