Make a Self Tapping Bolt

Sometimes you may need to add threads to a hole, but you don't want to go buy a thread tapping tool. Making a self tapping bolt is quick and easy. It works great if you need to tap some plastic or wood, but it may not be the best option for thick metal. Either way, Here are the steps for making one.

If you would like to see a video version of this instructable, you can check that out here: https://youtu.be/cg1nVvXhTbA

Supplies

• Custom Screwdriver
• 1/4" Drive Screwdriver Bit
• Pliers
• Dremel
• Grinding Stone
• Cutoff Wheel
• Drill
• Drill Bit
• Bolt

Step 1: Taper the Tip

Simply grind or file a taper onto the tip of the bolt. The bolt will get hot, so it helps to hold it with some pliers.

Note: You don't have to taper the tip of the bolt, but it does help to get the bolt started when you're using it.

Step 2: Add Some Grooves

Next you'll want to add some vertical grooves into the threads of the bolt. I recommend adding either 3 or 4 grooves, depending on how big the bolt is. These grooves add an opposing sharp edge to the threads of the bolt to help cut the threads into the material when screwing in the bolt.

That's all there is to making a self tapping bolt, but I added a couple more steps to help describe using the bolt.

Step 3: Drill a Hole

When drilling the hole in the material, you want to make the hole a little bit smaller than the diameter of the bolt. If you make the hole too big, there won't be enough material for the threads to hold on to.

NOTE:

Obviously, this isn't the proper way to create a strong, watertight seal for PVC connections. I'm just using this on PVC because it's adequate for demonstration purposes here.

Step 4: Screw in the Bolt

This step is mostly obvious, but there are a couple things to remember. First, try to keep the bolt perpendicular to the surface. Next, you want to push the bolt in as you turn it. This will help it to bit into the material as it's starting to cut the threads. And finally, don't just screw it in all at once. Every now and then, turn the bolt backwards about half a turn. This helps it to cut better threads into the material.

Step 5: And That's It!

And that's all there is to it! This works good if you need to make threads in soft material, or thin metal. If you need to thread a hole in thick metal, you may be better off getting a thread tapping tool. Thanks for checking out my Instructable!

Comments

[ray.m.dicker]

Hi there. Another way of doing this, take a bolt and nut. Screw the nut onto the bolt, mark off one-third increments, punch on the joint of the bolt and nut and drill three holes, and there you have a tap and a die-nut. You can even use a HT bolt to get a stronger tap.

[cwtears]

This has saved me a lot of time over the years. I have mainly used where a scew or a bolt has been damaged and I don't have a spare. I don't own a Dremel so I use by bench grinderand i find that three points helps to self center the scre a little more easily.
When I am joining soft materials I use drill taps. The are great for speed and ease of use and are very inexpensive on places like Bangood, Alibaba and Ebay.

[How Do You - DIY]

I really like the idea of making use of what you have available. Thanks for sharing your version! I haven't though about trying to do it like that. It makes a lot of sense.

[cwtears]

Aother little tip. I have a jewellers saw and when I find the threads on a bolt are a bit tight, a couple of slots cut in the thread of the nut can work wonders.

[How Do You - DIY]

That's a really cool tip that I haven't thought of. It's easy for a bolts threads to get damaged, and your tip is a great way to help with that. Thanks for sharing the tip!

[MarkH342]

That is neat, and the simplest thing I've seen here. It reminds me of a time when I spent an entire work shift shortening tiny #2 screws on a bench grinder. They were special screws, ordered slightly too long, and no time to order the correct length. A fond memory.

[How Do You - DIY]

Sounds like "fun times"! It can be handy to be able to quickly modify what you have to get what you need.

[jon_chalk]

Very simple to follow. Clear and concise explanations. Now I understand what is a self tapping screw. 👍

[How Do You - DIY]

Thanks! This trick can come in handy in a pinch.

[rdy4trvl]

Oh great, the cat is out of the bag - now everyone knows how to connect PVC pipe without glue. You've just put all the glue PVC glue & primer manufacturers out of business.
Seriously, I never thought to create my own - great for that one-off need and it's not worth buring an hour to get one at the store.

[How Do You - DIY]

😂 I forgot to add a disclaimer that this isn't the proper way to connect PVC pipe. But yeah, this has come in handy for me a few times when a watertight connection isn't necessary. (or a temporary connection is preferred)

[HugoF48]

self tapping bolt....MEANS....you dont need to drill an hole first !

[How Do You - DIY]

I used to think the same thing... until I saw a self tapping bolt that doesn't drill the hole. What you're describing is a self drilling bolt. They drill and tap the hole at the same time. Tapping a hole is adding threads to a hole.