• Controllable — M55x1.5 fine thread advances 1.5 mm per turn, so a 1/6 turn gives axial resolution better than 0.01 mm, and it repeats where shim trial and error does not.
• Lockable — once preload is set, a radial locking plug presses on the thread so it does not back off under vibration and heat; plug hole to thread axis perpendicularity 0.05 mm.
• Repeatable — drawings specify preload torque and axial displacement, so assembly follows a torque wrench instead of operator feel.
• Holes still need to be accurate — thread seat to bearing bore coaxiality 0.01 mm and face-to-bore perpendicularity 0.01 mm, otherwise preload tilts the bearing and shortens its life.
• Thread quality — 6g class accuracy, 100% go/no-go gauging, thread roots left unpolished to avoid altering the pitch diameter.

Preload method is tightly coupled to bearing layout, so it is custom to each joint design.

• Thread specification — M45-M70 fine threads with 1.0/1.5/2.0 mm lead selected by adjustment precision.
• Locking method — radial plug, face lock tab or thread adhesive, selected by maintenance frequency.
• Bearing fit — deep groove or paired angular contact or crossed roller bearings, with shoulders and spacers matched to preload requirements.
• Material Options — aluminum for weight, 40Cr for thread wear and fatigue life, stainless for corrosion resistance.

The drawings of a complete humanoid robot are often the core competitiveness of the next machine generation. We apply both physical and data isolation on a per-project basis.

• NDA First — mutual NDA and non-circumvention agreement signed before drawings are received.
• Isolated Secure Area — dedicated machines and staff, no photography and no phones inside the area.
• Not displayed — drawings, part photos and customer logos never enter sample cabinets, catalogs, the website or social media.
• Data Isolation — programs and models sit on an access-controlled server, destroyed at project end with a written record.
• Code-named — traveler cards and packaging labels use internal codes instead of customer part numbers.

Dongguan Changxinda Precision Technology Co., Ltd.Founded in 2008, with a team of 90-102 staff, serving 200+ Customers, export share 50-60%, annual sales of USD 10-20 million, ISO 9001:2015 certified.

We like to turn assembly feel into numbers on a drawing: preload, axial displacement and locking torque are all written as inspectable values, so results stay the same when you change a line or an assembly operator.

• Reserved Capacity — machine time is locked weekly for volume programs, so rush orders never displace batch schedules.
• Two shifts, six days a week — production runs 07:30-22:00, with weekend shifts added in peak season.
• Buffer Stock — semi-finished stock is held for repeat specifications, cutting repeat order lead time by about 30%.
• Visible Progress — weekly progress sheet plus shop floor photos, tracking number issued at shipment.
• Shipping — samples by express in 3-5 days, volume by air or sea, EXW / FOB Shenzhen / CIF.