Tapping

Form tapping can be performed on the zinc alloys over a wide range of conditions. Form taps are fluteless and much stronger than fluted cutting taps, making them especially useful for small diameter holes where tap breakage is a potential problem. Form tapping also eliminates congestion of the small flutes. Form taps are more expensive, give poorer thread shape and require more accurate hole diameters than cut thread taps but they do have the considerable advantage of producing no swarf and the strength of the thread produced is equal if not better than a cut thread, (except in respect of torque relaxation). The recommended tapping speeds for form tapping are the same as for cut threads. Cutting fluids are especially important because the process generates high frictional forces. Water-based oils or light mineral oils are suitable.

In most cases, tapping is performed on cored holes in the diecasting without any drilling operation. If this is not possible holes can be drilled prior to tapping. Please see our drilling section for more information.

In general, type “S” chasers having a curved rake face and a throat angle of 33° should be used. The back rake should be 25° with a 4° negative side rake and 12° clearance. The work zone should be well lubricated, and a slow feed rate employed.

Tapping involves machining a thread into a cored hole. Whether it be cut tapped or roll tapped it will be machined on our fully automatic tap-matic machine and will be checked with a fully calibrated screw gauge to ensure it is fully formed.

Yes, all components have their own custom-made fixture to suit the individual needs of the product.

Whether it be cut tapped or roll tapped it will be machined on our fully automated tap-matic machine. The component will be placed into a fixture and automatically threaded; we can tap up to 6 holes at a time making it a cost-effective process.