Clarke CHT303 28-piece Metric Tap & Die Set review

If you’ve never had the displeasure of a cross threaded engine casing mounting hole, or frame mounting point for, say, bodywork, we can assure you that this forehead-scrunching, sweary explosion moment isn’t far away. To be honest, based on our experience, anyone who is attempting a barn find or other resto project will get nutted by the full force of corrosion on just about every fastener they come across. Guaranteed.

All Japanese and European motorcycles feature metric fasteners. Even modern Harley-Davidson bikes feature metric nuts and bolts but only because their global parts suppliers are the same manufacturers who supply Japanese and European-produced bikes. The ‘evil imperial thread empire’ is falling. Thank gawd.

So, you come across a bolt that was a real pain to remove – needed some extra muscle to get undone and metal debris or white/rust oxidation (corrosion) came out with it. What do you next? Well, we reach for the tried and trusted Clarke CHT303 28-piece Metric Tap & Die Set. A what, you say?

In a nutshell, a tap and die set makes or repairs threads. “Taps” are used to cut/recut internal (female) threads, where fasteners, e.g. engine case bolts, are screwed in. Dies make or repair threads onto a fastener (male), e.g. a 5mm hex-headed bolt.

The most common motorcycle fasteners to be removed, as said, are sized M4 to M12. “M” denotes metric; the following number references the thickness of the fastener’s shaft. Therefore, using M4 as an example, it is a metric bolt with a 4mm shaft. However, there’s another number associated with every fastener, and it is equally important, the “pitch” of the thread – the distance between threads. This too is measured in millimetres.

The 28-piece Metric Tap & Die Set is perfect to renew or make new the most common threads to be found on a bike. The 28-piece set consists of eight starter and finish taps, with eight matching dies. The sizes covered are: M3 x 0.5mm, M3.5 x 0.6, M4 x 0.7, M5 x 0.8, M6 x 1, M8 x 1.25, M10 x 1.5, M12 x 1.75.

Two adaptor handles are supplied to fit the taps into and enable a good grasp to make light work of turning the taps to create/renew (chase out) a thread. The large handle unit is ideal for the bigger taps (8-12mm), The smaller handle can hold all supplied taps but is better suited for the smaller diameter taps and if the working area is a bit tight on space.

The external thread cutting dies share the same supplied tap sizes and material specifications, which incidentally is tungsten steel. Interestingly, the dies are split type, which makes it easier for swarf/debris removal.

We’ve extensively used the Clarke CHT303 tap and die set on aluminium, steel and stainless-steel parts without any problems. But saying that, we are very cautious with every thread we’ve had to chase; only quarter to half a turn of tap or die before firing a bit of lubricant onto/into the thread area. Another plus point or two is given because the CHT303’s tool set is stowed in a metal case for safekeeping.

Bigger thread sizes can be catered for with bigger Clarke Tap & Dies Sets. We are talking about wheel spindle threads (male and female) and engine mounting points. But for everyday use and at its present point of £35.98, the Clarke CHT303 Tap & Die Set is a must have bit of kit for anyone who knows how to fit a 3/8th drive socket to a 1/2in drive ratchet.

To find out more or to buy, head to the Machine Mart website.

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