Union Butterfield Self-Locking Taps

Union Butterfield Self-Locking Taps

Dormer Pramet puts a lock on fastener costs with its Union Butterfield brand of self-locking taps. Utilizing specialized production equipment, this self-locking thread form can be produced on straight flute, spiral flute spiral point, roll form and even on the Union Butterfield line of high performance taps.


With improved holding power that lasts, the self-locking tap design eliminates time intensive disassembly and assembly procedures and costly fasteners, chemical bonds, nylon plugs or other devices to maintain tightness. In short, the company’s taps provide efficiency in operation and cost.

A 30° wedge lock on the female thread creates a continuous spiral contact along the entire thread length for improved holding power versus standard thread forms.

Working with aluminum or other lightweight, soft materials? The optimum load distribution provided by Union Butterfield’s self-locking thread form eliminates thread stripping that is typical when clamping load is concentrated on fewer threads. Clamp load forces with the Union Butterfield self-locking thread design are spread evenly across all threads as compared to a conventional 60° thread form that puts clamping force only on the first few threads with the other threads receiving limited or not contact at all.

Ideal for transportation, medical or industrial use, these Self-Locking taps will deliver holding power that lasts.

About Dormer Pramet
Dormer Pramet brings together a program of rotary and indexable tooling with more than 150 years of industry experience. Our teams and brands reliably meet your requirements  and, although our company has changed names through the years, one driving factor remains: We continue to work hard to be your reliable partner with a comprehensive cutting tool offer.

We deliver the market-leading brands of Precision Twist Drill (PTD), Union Butterfield, Master, Dormer and Pramet to our global customer base. Our core offer includes drilling, milling, threading and turning tools for the general engineering sector.

As your one-stop-shop cutting tool manufacturer, we partner with customers through online e-learning modules and training. As your full service supplier, we are committed to helping our customers carry out their machining processes efficiently with productivity as our goal.

For more information please visit us at www.dormerpramet.com.