instructables All About Tapping for Screws and Bolts by clickclackclunk Just letting you know that this article has affiliate links called threading. in it that hopefully will help me pay the bills and keep writing more! If you want to help me out just click here It all sounds complicated and harder than what a and buy whatever you were going to buy anyway. I beginner would want to deal with, but I'm here to tell really appreciate it! :) you otherwise! With a little practice you will be able to drill and tap your own holes, and cut your own == threads! It's really not all that hard. This article is a continuation on my "All about What you'll probably need: screws" article. If you haven't read that one, please do now. If you're just getting started you probably don't have a tapping set. These will come in either imperial or What is tapping? metric and can run the range from fairly cheap to uber expensive. You get what you pay for, and a quality set will break less and last you longer. For a Tapping is the process of cutting a matching set of beginner, get the cheap set and break them and learn threads into a piece of metal, plastic, acrylic, or wood. what you can and can't do. It's going to happen The process of tapping uses two separate tools: the anyway, so don't throw your money away! tap which cuts the threads on the inner diameter of the hole, and the die which cuts the threads on the You'll also need some sort of cutting fluid. Without outer diameter of the bolt or screw. this you're going to have a bad time of it. Lubrication is the word of the day. Buy some cutting fluid. Trust The process of cutting the threads using a tap is me. called tapping, and the process of using a die is All About Tapping for Screws and Bolts: Page 1 Step 1: Types of Taps and Their Uses A tap cuts threads on the inner diameter of a hole, threads in the taper is typically 8 to 10. like a nut. There are a few main types of taps: Powered Taps Plug Taps (or Second Taps) These are the most commonly used taps as they are easiest to line up and start your threads. The have a While the previous taps were the types that you gentle taper in the business end of the tap, which is would use manually, there is also a type of tap that used to center itself in the hole you are threading. The you'd use in a lathe, a mill, or a drill press. These number of threads in the taper is typically 3 to 5. powered taps, commonly called a "spiral point" tap are usually used in holes which go all the way Bottoming Taps through your working material as they break and eject the chips forward, into the hole. These types of taps allow you to cut all the way down Forming Tap into a blind hole (a hole that doesn't go clear through your material) and have threads to the bottom surface. This type of tap is usually used after you've The above tap types are cutting taps, where they already partially threaded your hole with a tapered actively carve a groove into their working material. tap. The straight edges at the beginning of the tap The forming tap pushes the material back into itself to make it very difficult to accurately line up the tap with form the threads. These taps, since they do no cutting the hole you are tapping. work, do not have flutes (cutting grooves). These types of taps are utilized in forming threads in blind Tapered Taps hole since they do not create chips and do not need to be backed out. Since the method of forming threads is by pushing the material into itself, this These taps are similar to plug taps as they have a method is generally only used in softer materials like taper in the head of the tap. A tapered tap has a more mild steel, brass, and aluminum. pronounced taper, and this allows for a less aggressive cut for cutting threads. The number of All About Tapping for Screws and Bolts: Page 2 Step 2: About Dies Dies are used to cut the outside threads which will on to and cutting. mate into a threaded hole or nut. This is what cuts the "male" part of a thread. Dies are generally made in Chasers or Die Nuts two types: solid and adjustable. The solid ones are a set size, and the adjustable ones have a screw or set of screws which allows you to make the threads There are a second, related set of die-types which are slightly tighter or looser depending on your need. called chasers or die nuts. These are used for cleaning up old threads which have become worn Dies are used with a die wrench, which fits around from use or corrosion. Chasers can not be used to cut them and gives you leverage over the cutting new threads! The generally come in a set size and process. These wrenches generally have a centered have a hexagonal shape for use with a wrench. hole for the die to fit into, and two handles for holding Step 3: Tapping Fluids At this point I want to talk a little bit about tapping the chips with pressurized air. fluid. As I mentioned earlier, it is critical that you use some sort of lubricant. What you use depends on On Aluminum use kerosene or mineral spirits with a what you are cutting into. small amount of petrolum cutting oil. WD-40 is often a decent substitute for tapping aluminum. For mild steel, use a petroleum or synthetic cutting oil . When tapping brass, use kerosene or mineral spirits without anything else. For alloy steel or stainless, use a petroleum cutting oil and mix it with kerosene or mineral spirits, 9 parts oil Finally, with bronze, use kerosene or mineral spirits and 1 part diluter. with a small amount of petrolum cutting oil. Do not use a lubricant on cast iron! You can clear out All About Tapping for Screws and Bolts: Page 3 Step 4: How to Tap Threads Start by defining the correct size. If you have a screw Place the tip of your tap into your hole. Keep the tap or bolt that you are targeting, look up the size and as perpendicular as you can and apply downward required hole for tapping. Wikipedia has a good chart pressure. Start turn your tap slowly clockwise. The that can help you figure out what size your hole teeth of the flutes will catch and you'll start cutting should be. Many taps will have the required hole your threads. Every few turns carefully back out your written on the side of the tap. tap and clear the chips. Drill your hole, trying to keep it perpendicular to the I can't stress this enough: go slowly and clear your work piece. A drill press is a great way to do this. If chips. The most common reason for breaking a tap is you don't have a drill press handy, you should look at that a chip will get wedged in between the tap and the using a jig. wall of the hole you are trying to thread. The tap is not strong enough to withstand the shearing forces and Countersink the mouth of the hole. This will help will snap. Trust me that you don't want to have to deal guide the tap into the center of the hole and help ease with getting a broken tap out of a hole you critically the flutes into starting the tapping process. need. Once you're ready, you can grab your tap and tap Keep this process up (twist, untwist, clear chips) until handle. Unscrew it until your tap fits in, and screw it you've worked your way all the way down. Apply down until it is tight, but not so tight that you won't be more fluid if you think that it has run all away or if able to get it open again. Everything in moderation :) you've had to wipe it away because you were clearing chips. Clamp your workpiece down or use a vice. You won't be able to hold it down with your hands as you'll need Test your newly tapped hole by screwing in a mated both for guiding and turning the tap. screw or bolt. If this is a custom hole size, you'll need to first use a die to cut a matching thread. Apply some tapping fluid to your tap. Check the section on which fluid to use for your material. All About Tapping for Screws and Bolts: Page 4 Step 5: Using a Dead Center to Make Your Life Easier If you are already somewhat accustomed to working Take a look at one of my favorite blacksmiths doing it with a tap and have found that getting things lined up here. just right is a pain, I highly suggest using a dead center in the chuck of a drill press to make sure that Hope that helps someone :) you have even pressure applied perpendicular to your work piece. All About Tapping for Screws and Bolts: Page 5 Step 6: How to Thread Using a Die The process of threading using a die is very similar to secure it in place.