Stainless Steel Threaded Nozzle Adapter Bushing with 0.008mm Bore Alignment and Knurled Grip for Automated Welding Cells

This threaded nozzle adapter bushing is the interface between the torch neck and the consumable nozzle on an automated welding cell. On a robot, the nozzle position sets the gas shield and the contact tip height, so a bushing that seats differently after every change will move the working point and cost you re-teaching time. We machine the internal thread and the locating bore in one clamping and hold their alignment to 0.008 mm, so a replacement bushing seats in the same position as the one it replaces.

The outside carries a straight or diamond knurl for gloved-hand changes without a wrench, and the lead-in chamfer is cut at 15 degrees so the nozzle starts square instead of cross-threading. Options include an anti-seize coating for aluminium nozzles and dry film lubrication for high-temperature cells.

1. 1Drawing and process review. We check thread callout, bore depth, knurl type, wall thickness and the alignment requirement, then issue a process plan and quotation within one working day.
2. 2Material verification. Stainless bar is checked against the mill certificate; 17-4PH is confirmed for heat-treat condition when a harder thread is specified.
3. 3Cutting and stress relief. Blanks are cut with facing allowance and stress relieved where the wall between thread and bore is thin.
4. 4Turning of bore and body. The locating bore, shoulder, knurl diameter and chamfers are turned in one programme, with the bore finished to H7.
5. 5Thread milling. The internal thread is milled on the same machine, using the bore as the reference, which keeps the thread axis and bore axis within 0.008 mm.
6. 6Knurling and deburring. The grip band is knurled to the specified pitch, thread starts are chamfered, and the bore is deburred from the inside.
7. 7Passivation and marking. Parts are passivated after machining, then laser marked with the batch code outside the thread and locating face.
8. 8Inspection and packing. Go / no-go thread gauges on every piece, air gauge for bore, alignment check on a threaded mandrel for critical jobs, then tray packing with foam.

On a manual torch, a nozzle that sits 0.05 mm off centre is invisible. On a robot running the same programme for weeks, it changes the gas coverage and the contact tip height, and the operator compensates by re-teaching the TCP. Keeping thread and bore alignment at 0.008 mm means a spare bushing drops in without touching the programme. We check this on a threaded mandrel with a dial indicator, and for critical cell applications we check every piece rather than sampling.

Every dimension is built to your torch and your cell: thread size, bore diameter and depth, shoulder position, knurl pattern, overall length, material grade, heat treatment and coating. 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 feature would raise cost without improving function, our engineer returns a DFM note with an alternative and waits for written approval before production.

• 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 portfolio use. Confidential bushings never appear in samples, catalogues, website pages or trade fairs, and photographs require written release.
• Dedicated cell. Sensitive jobs run in a segregated area with named operators; programmes and fixtures are stored under a project code, not the customer name.
• Controlled partners. Passivation and coating suppliers receive the process specification only, never the assembly drawing or the robot application.
• Internal traceability. Batch records are kept for three years so quality questions can be answered without exposing the design.

• Confirmed dates. Prototypes in 3 to 7 working days, batch orders in 12 to 20 working days after drawing approval, written into the order confirmation.
• Fixed slots for repeat parts. Blanket orders reserve machine time, so the same bushing arrives in the same week each month.
• No re-programming. Programmes, fixtures and gauge sets stay on file, removing setup time from the second order onward.
• Early risk notice. If material, knurling, passivation or gauging threatens the date, you hear it before the date is missed, with a partial shipment option.
• Dispatch evidence. Photos, inspection report and packing list before shipment; tracking number on the day of dispatch.

• 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 bushing is packed in a bubble bag, seated in a custom EPE cavity tray so threads and knurls 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; neutral cartons are available for customers selling under their own brand.

Dongguan Changxinda Precision Technology Co., Ltd is a custom machining manufacturer established in 2008 in Dongguan, China. We operate four-axis and five-axis machining centres, turn-mill combined lathes, CNC lathes and milling machines, employ 90 to 102 people and work to an ISO 9001:2015 quality system. Over 200 customers have been served, 50 to 60 percent of output is exported, and annual sales sit between USD 10 million and 20 million. Our engineers build from drawings rather than a fixed catalogue, so a threaded bushing with a specific alignment callout is standard work for us.