Your Guide to Buying a Tap and Die Set

A good quality tap and die set is essential in any workshop, repair or maintenance bay and it can be a handy tool to have around the house too. There’s a lot of different options when you look to buy a new tap and die set though, so we’ve come up with this handy guide to explain what tap and die sets are, how they are used and what to look out for. 

Firstly: what is a tap and die set? 

A tap and die set is used to make threaded holes and rods to connect pieces of metal or other materials. They can make threads from fresh materials, and are also commonly used to repair or clean damaged, stripped, or aged bolts and screws. 

How does it work? 

The tap is used in conjunction with a tap wrench, and cuts an internal thread, essentially forming a nut. The die is used in conjunction with a die holder and creates the external thread – making a rod into a screw or bolt. 

What are the benefits? 

For precision work, keeping internal and external threads clean and sharp creates a tighter fit and better hold. 

For larger pieces of equipment, having the ability to repair a stripped or damaged thread means you can avoid having to replace expensive kit. 

In fabrication, being able to create threads wherever you want gives more freedom. 

What types of tap and die are there? 

There are three main types of tap: the taper, the second and the plug.  

• The taper tap is used to initiate the thread, and usually has a tapering effect from the bottom upwards 
• The second tap is used to deepen the cuts made by the taper tap 
• The plug tap finishes the thread neatly near to the end of the hole 

Dies are broadly split into two main types: circular and adjustable. The circular die creates complete threads in one operation, while the adjustable (or two piece) can be used for longer threads and involves a number of cutting operations. 

What options are there? 

Tap and die kits come in a choice of either metric or imperial measurements – so before you buy, make sure you are looking at the correct sizing. Most kits will have a good number of pieces (anywhere between 20 and 80), with a range of different sizes and thread gauges. Be sure to pick the set that contains the pieces you need. Split dies are easier to use as they can be adjusted precisely and minutely. For professionals, you’ll want to look at HSS (High Speed Steel) taps and dies, for a superior cut and a long-lasting part.  

If you’re a mechanic, you will probably need a kit that includes hex-shaped dies – you can use these with standard sockets and spanners.

Author Bio: First Mats started life as safety matting specialists, but have since expanded to become a complete industrial and commercial supplies company. The focus of First Mats is to provide safety-focused products that improve the wellbeing of staff through quality approved products, backed up by extensive knowledge. www.firstmats.co.uk