The tap is the key to finely machined pieces when it comes to machining. You will need to drill a hole and then use the appropriate tap according to a tap chart and drill.
But, its not quite as simple as it seems. Today, were going to cover how to use a drill and tap chart and take a look at some of the best drill and tap sets that are on the market today.
What Is A Tap?
A tap is a tool that features a threaded midsection, just like a screw or bolt would. A tap takes a hole in the material and adds threads to it, so its able to mate with the appropriate fastener. You must drill a hole through the material before you can use a tap. You will need to measure the size of the hole to match the tap. Once you have created the hole, use a tap for adding threads to the metal you are working with.
Why Tap Holes?
With machined parts, its often necessary to add female threads to a piece of metal so that they can mate with a screw to provide a solid assembly. You could tap the hole and use a nut to attach the fastener on the other side. Tap the hole and attach the hardware directly to the metal is the best option.
What Is A Drill And Tap Chart?
A drill and tap chart, a large diagram that shows all the information needed to tap holes correctly, is called a drill and tap chart.
Each chart includes values for the screw size, major diameter and minor diameter. From there, they tell you the proper size drill bit to use to make the hole for the tap. If you are drilling a hole for a fastener, such as a nut, the chart will tell you the right size bit.
This drill and tap chart covers everything you need. This reference can be saved to your bookmark so that you can refer to it whenever you need.
Drill And Tap Conversion Chart
How To Use A Drill And Tap Set
Using a drill and tap set is quite easy. The key to producing properly tapped pieces is to make sure everything you do follows the drill and tap chart.
First, identify the fastener size youll be using on the tap chart. You will then be able find the right bit to make the hole.
Next, insert the drill bit. A drill press is optimal for tapping holes, but if you dont have one in your shop, a corded or cordless drill will do the trick just fine. Put on safety glasses to protect yourself from any flying debris, and drill out your hole.
Once you have your hole, you can tap the hole to add the threads.
First, secure the piece youre working with. If the piece is too big for a bench vise, you can use clamps to hold it in place. Grab the corresponding tap from your tap kit, and attach it to the tap wrench. You can also use a shorter version of the t-handle wrench if you don’t have enough clearance.
Place the tap in the hole and stand directly above your workpiece. Now, apply gentle pressure and begin to screw the tap into the piece. Within a turn or two, you should feel the cutting threads as they bite into your workpiece.
Apply gentle pressure to the tap and continue turning it. For each clockwise rotation, you make, rotate the tap back out a half turn counterclockwise. This will remove any metal that may have remained when the tap entered the metal and ensure a properly tapped hole.
Repeat this process until the tap has passed through the entirety of the workpiece, and then remove the tap. You should now have a properly tapped hole ready for you to attach a fastener.
Best Tap And Drill Sets
Now that youre armed with the knowledge you need to properly tap a hole lets take a look at a few of the best drill and tap sets that are on the market.
Irwin 117-Piece Deluxe Drill And Tap Set
This kit is for the machinist who needs a complete selection of taps.
Included in this set are 117 of the most common plug tap, and hex die sizes, screw extractors, drill bits, wrench handles, and pitch gauges. All items are neatly packed in a plastic case.
What We Like
- A comprehensive range of taps is included
- Multiple tap handles have you covered for every application
What Could Be Better
- Expensive
Bosch BDT11S 11-Piece Drill And Tap Set
If you just need the basics for occasional use, you cant go wrong with this set from Bosch.
This kit contains #7, 21, 25, 29, 29 and 36 bits and the corresponding taps. Laser engraving is done on each bit to indicate the size of each tap and bit. The sizes are also printed on the inside of the case, so youll be able to put each bit back in its proper place when youre done. Also included is a deluxe tap wrench. This set includes everything in a high-quality case.
While it doesnt include a broad range of different sizes, this kit represents the most popular fastener sizes, making it perfect for basic jobs.
What We Like
- Includes the most popular tap sizes
- Included tap wrench is perfect for use in low-clearance situations
What could be better?
- Only includes five different taps
AccusizeTools 18 Piece Drill And Tap Set
This set from AccusizeTools is incredibly well made and includes a few extra taps you wont find in the Bosch kit we covered above.
The kit contains nine popular taps and bits, all in a sturdy steel case. Each bit contains HSS fully ground steel, so it should stand up to anything you can throw at it for many years to come.
This kit is more complete than smaller ones, so it’s ideal for the machinist that needs many taps and doesn’t want to spend hundreds on a bigger package.
What We Like
- Offers a wider range of sizes
- Steel case with clear bit markings
What could be better?
- It doesn’t include a tap wrench
Final Word
Tap charts and sets, as well as drill and tap charts, are some of the most difficult tools you’ll ever need. Once you know how to read and use taps, you’ll be able to create beautiful pieces in your shop.
