Thread whirling
Whirling of high-quality heavy-duty threads — typically acme or trapezoidal — on long lengths from Ø25 to Ø105 mm, up to 2.2 m.
Overview
Thread whirling is a machining method of producing high-quality heavy-duty threads — typically acme or trapezoidal — on long lengths of material. A ring of cutters orbits the workpiece, cutting the thread in a single pass with a superior surface finish and minimal residual stress. Such threaded shafts are typically required for lead and feed screws. At Robb & Carter we generate these threads on material from about 25 to 105 mm diameter, for lengths of up to 2.2 metres, on three dedicated thread whirling machines.
Typical applications
- Lead screws and feed screws
- Long acme / trapezoidal threaded shafts
- Multi-start power screws
- Recoverable anchor screw threads
- Tie-rod and actuator threads
Capability data — Thread whirling
- Machines
- 3 thread whirling machines
- Thread forms
- ACME / trapezoidal, multi-start and custom heavy-duty profiles
- Diameter
- Ø25–105 mm
- Length
- Up to 2.2 m in a single whirling pass
- Finish
- Superior surface finish, minimal residual stress
- Typical use
- Lead screws and feed screws
Also in-house
CNC milling
3-, 4- and 5-axis milling of prismatic and complex parts, from prototypes to 100k-part production runs.
CNC turning
Bar-fed and chucking lathes with live tooling for shafts, pins, bushings and rotational parts up to Ø600 mm — 480 000+ parts per year.
Forging
Closed-die and upset forging with in-house die design and machining; larger forgings and heat treatment routed through trusted specialist partners.
Insulated railway joints
Manufactured insulated rail joints for track circuits and signalling isolation, built to take repeated wheel loads.
Recoverable anchor screws
Recoverable roof- and side-anchor screws for underground support — engineered to be installed, loaded and withdrawn intact.
Thread rolling
Cold-rolled external threads up to M64 — strong, smooth, precise and uniform forms produced with no chip loss.
Hot-forged bolts
Hot-forged bolt blanks and special fasteners from forged bar, with rolled threads and full material traceability.
Toolmaking
Design, manufacture and maintenance of dies, fixtures, jigs and gauges — the tooling that keeps production running.
Industrial fasteners / thread machining
Standard and special industrial fasteners from 20 mm diameter up, with thread machining — cutting, chasing and grinding — to drawing.