Why taps are my favourite…


Rob Sutton explains his belief that there are two distinct kinds of people in the world and confesses his lifelong love affair with taps.



My love affair with taps began at a physical level in my school days while working at the factory during the summer holidays. That passion continues to this day, based on the philosophical concept of value add. I am a confirmed Tap Person.

To the uninitiated, a tap is a simple tool for cutting a thread into a drilled hole. This notion belies the subtlety of these tools and their profound effect on civilisation as we know it. In fact, you can cite the invention of a standardised 55-degree thread form by Joseph Whitworth in 1841 as a defining moment in world history.


It’s pretty safe to say that we would not be flying to London (or anywhere else) without tap thread technology for fastening parts. We might not even be sailing there in a metal ship… Look around at any mechanical device with any degree of sophistication, and you’ll find it is fastened with threads.


From a catalogue range perspective, the manufacture of a tap range is a logistical miracle in itself. The range of differently dimensioned blanks cover a variety of sizes and standards around the world. Perversely, each corner of the world seems to have deliberately developed its own dimensions – commonly identified as ISO, DIN, JIS and ANSI. Each of these blanks have a 10mm tap, but with completely different dimensions. It’s actually not unlike Australia’s old railway gauge widths, where a train from one state couldn’t travel over the border – so passengers had to pile out and change trains. The taps will make a 10 mm thread, but the tap won’t fit in the holder of the collet!

Compounding this, taps have multiple thread forms with multiple geometries over four basic design types – which makes for a truly staggering possible combination of tools.


It’s hard not to love a tool with a basic theoretical diameter tolerance of 10 microns that requires a gauge to assess the outcome in use. Diameter is really just a stepping off point; the tap thread form geometry is compounded by a wonderful confluence of flute helix angles, rake angles derived from multi radii flute shapes, raw material section and heat treatment and finally coatings and surface finishes.


From its most basic form as a hand tool through to micron-perfect balanced production tools capable of producing volume threads in exotic alloys, tap manufacture dose border on a Black Art. (Hence Sutton Tools’ Black Magic range). The sublime subtlety of tapping leaves all other applications eating dust, as far as I’m concerned!


At Sutton Tools we produce taps, endmills, drills and a very wide variety of cutting tools. Having spent countless hours discussing the subject with other Cutting Tool People, I am completely convinced that our section of the world is ruled by Taps People. Sadly, it’s a club that gets smaller each year as global consolidation strengthens its grip on our industry.

But taps will always be our passion – and, with dedication, will always be very much alive wherever innovative, independent companies thrive.