Threadmaster grinds out quality

Although there are a number of methods for measuring internal and external diameters, the ubiquitous plug-gauge and ring-gauge remain the most common means of gauging IDs and ODs. However, the high levels of precision required in the production of these gauges mean that, in the UK, they are made by just a small number of specialised gauge manufacturers.

A leader in this field is Kenilworth-based Threadmaster Gauges Ltd, which manufactures plug and ring gauges in both plain and threaded formats. Moreover, the company exports more than 40% of its output; it also invests regularly in new production equipment, as company owner George Ratcliffe explains. “As threaded plugs and rings are normally produced as one-offs, or occasionally in very small batches, they have traditionally been produced on manual grinding machines. To keep up with growing domestic and international demand, and to enable us to manufacture high-quality products at the right price, we have purchased four external CNC grinders over the past few years for the external thread-grinding of our thread plug gauges. Last year, we began to research internal CNC grinders for producing internal thread ring gauges.”

Following a demonstration by Micronz Ltd (www.micronz.co.uk) — the UK Studer agent for the North and Midlands — Threadmaster bought a Studer S33 CNC universal cylindrical grinding machine, which features a Granitan base to optimise dampening properties and surface finish, as well as grinding-wheel life.

Studer’s turret wheel-head, with two motor spindles and an internal grinding attachment, enables the grinding of more-complex workpiece geometries in a single clamping, as well as both live-spindle grinding and grinding between centres. The machine can also be fitted with a specially designed chuck work- head for chuck applications, and fine adjustment allows for taper corrections — within the 1um range — throughout live spindle operations. Control is via Fanuc 0i-TD CNC with integrated PC and 15in touch-screen.