Manufacturing

For an air shaft or safety chuck to run smoothly on a machine, the work starts with choosing the right material and ends with a final test before dispatch. This page outlines the steps our products go through. Technical values for each product are given in the tables on the relevant product pages.

Body: aluminium profile and steel tube

The bodies of our aluminium air shafts are made from profiles produced by aluminium extrusion. An aluminium body is light, which helps where operators handle shafts frequently. On steel air shafts, the body is made from special alloy cold-drawn tube, giving the strength needed for heavier rolls. The lugs on the shaft are made of steel.

Journal machining: CNC to drawing

Shaft journals are made from hardened special steel and machined on precision CNC machines to the customer’s technical drawing. Diameters and lengths outside our standard range are produced to order. Because we work to drawings, a new shaft can be made to fit the existing bearings and safety chucks of a machine that has been in service for years.

Hardening and surface treatment

Surfaces exposed to wear are induction hardened, and the outer surfaces of our safety chucks are hardened in the same way to resist impact. Surface protection is chosen to suit the material:

• Aluminium profiles are anodised (and varnished where required) to protect against corrosion and impact.
• Steel bodies are hard chrome plated to resist corrosion and wear.
• Shaft journals can be chrome, nickel, phosphate or zinc plated on request to improve corrosion resistance and surface quality.

Testing and dispatch

Before dispatch, our air shafts and adapters are tested for air tightness, strength and balance. The air tightness test checks that the air bladder and valve connection hold pressure, while the balance test checks that the shaft runs without vibration at high speed.

For questions about our manufacturing process or requests for special sizes, get in touch through our contact page.