Best Tap and Die Sets for Machinists
Taps and dies are used for two specific and similar purposes. Either you are cutting a threaded surface within a hole (a threaded hole) or you are cutting a threaded surface on the piece being inserted into the hole (bolt).
Ultimately both tools are working to develop the same type of surface, the difference lies in where that threaded surface is created. The tap develops the male portion of the duo while the die develops the female portion. The tap is used for the inside surface of a hole and the die forms the external thread found on the bolt, allowing the pieces to come together.
There are two ways to accomplish tapping and threading, either manually or with a machine. In this article we will discuss tapping by hand.
Tools You’ll Need For a Threading Job
Tap: The tap is the bit that is used to form the threads within the hole. Hand taps come in three different configurations.
The taper tap is used to start cutting the thread. The smaller diameter threads at the end of the bit make this possible. The plug tap is used to execute the main threading job. Some machinists use the plug tap for all segments of the tapping job, but this tap is technically not built for that. Lastly, the bottom tap is used to finish off the hole especially for through holes.
Tap handles: The handles are used to rotate the tap into the hole. They typically feature a mechanism that allows the bit to be held firmly in the center of the handles. Both tap and die handles come in a variety of sizes to accommodate many applications.
Die: The die is a circular piece that cuts threads into a rod-shaped piece.
Die handles: Like tap handles, die handles keep the circular piece locked inside the center of the handles.
Cutting oil: When tapping, it is important to lubricate the grooves. This will ensure that the metal chips are picked up (instead of falling into the hole), thus preventing any friction binding. Read more about cutting oil and which is right for your project in Cutting fluid: tips to save your taps.
Thread gage: The thread gage allows you to measure the pitch diameter of either the hole or bit to determine which size tap or die you will need. If you’re lucky, it’ll be included in your tap and die set. The gages used to measure taps are different than the ones used to measure dies. You can check learn more about them in An Introduction to Metalworking Gages (just scroll down to the Go/No-Go Gages section).
Screw extractor: Since the metal used for the bit must be harder than the metal being cut, the hardening process the bit goes through ultimately causes brittleness, thus is susceptible to breakage. Since broken taps happen often, screw extractors will be a life saver.
There are nifty sets that include the dies, taps, handles and thread gages. The screw extractor and cutting oil have to be purchased separately. If only there was a set including it all…any machinist entrepreneurs out there?
How To Use a Tap and Die Set
If you’re interested in learning more about the threading and tapping processes that tap and die sets are used for, check out the detailed video below.
The members on our forum shared not only their recommended models, but some good advice and their experiences to go along with it. You can check out that convo here.
Like other products, there are sets that will get the job done and there are high quality sets… for when you’re in the mood to splurge.
The Hanson tool and die sets are known for their ergonomic handles that allow more control and comfort when threading. The taps and dies in this set are self-aligning to ensure a straight tread every time.
Each high carbon steel tap and die in this set achieve maximum corrosion resistance with precision cutting performance. All the taps in this set are plug style and have the recommended drill size laser marked on the side for convenience and practicality.
The Morse tap and die set comes in a protective metal casing and contains 1/4 to 1/2 NC & NF HSS plug taps, 1/4 to 1/2 NC & NF carbon steel 1″ OD dies, a #3 die stock, a #4 “T” handle tap wrench and a screwdriver.
The Greenfield tap and die set features HSS taps and carbon steel dies. The set includes round adjustable dies and plug hand taps. These tools measure in imperial units.
This Craftsman combination carbon steel set will help you work with damaged nuts, bolts, and threads. Taps and dies made of hardened, precision-ground, and polished carbon steel surfaces to make chip removal easy. There is also a rust-resistant satin finish for smooth cuts with less friction.
This tap and die set is made of tungsten alloy high speed steel and is desired for its ability to start a thread easily, whether that be cutting new material or chasing lightly damaged threads. With proper technique and the right lubricant, these taps and dies will cut mild carbon and alloy steel, stainless steel, cast iron, aluminum, brass, and bronze.
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