Can I Drill Through Cast Iron?

Cast iron is an extremely durable metal. It’s used for a variety of purposes. You may be concerned about breaking the drill bit if you want to attach something or release pressure. It’s not nearly as difficult as you may think.

Any metal drill bit will work to drill a hole in cast iron. Cast iron is brittle and easy to drill. Drill slowly to avoid overheating or excessive friction, which can damage the drill bit.

Let’s look at what you need before we go into the guide on how to properly drill through cast iron.

* This article contains affiliate links. As an Amazon Associate I earn commissions on qualifying purchases.

What do you need to drill cast iron?

You will first need to buy a drill. You can check out my article about the best cordless drills if you don’t have one.

Cast iron can be cut with almost any drill bit, even the cheaper ones you buy in the discount aisle.

Cast iron is not resistant to the twisting action of a drill bit. You can therefore drill through it. You’ll only have to deal with the debris.

You can make your task easier by using a black-oxide drill. These drill bits are durable and won’t leave you with tons of metal shavings in your cast iron.

Try a cobalt-steel bit for added toughness. Cobalt steel is nearly impossible to break on cast iron.

These substances can cut through metals without dulling them.

Even better, you can get a drill with Titanium Nitride coating to help resist heat and friction. Even if it’s not hot, friction can quickly build up heat. Drill bits coated with TiN are believed to last up six times as long as the average bit.

ToolsOwner’s Choice

DeWalt titanium drill bits (21 piece set)

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Wearing safety gear is also a given. Choose goggles with temples and ears that will protect you. Do not forget to purchase a pair of durable work gloves. Choose a pair of gloves made from leather or canvas, to avoid slipping and possible harm.

Consider wearing clothing with long sleeves. Wearing denim jeans with a jacket and work boots will keep you safe. Safety always comes before anything else, even if you are a professional.

Alright! Let’s get started!

How to Drill Cast Iron

Prepare your tools for easy cutting before you start drilling.

Apply lubricant to your drill bits prior to using them. You don’t have to lubricate your drill bits if you only plan on drilling one or two holes.

cutting liquid is required for anything above that. can get a small bottle at a great price on Amazon. If you drill into metal a lot, I recommend that you get the 1 gallon bottle of cutting liquid . Cutting fluid will not only keep your bits safe but also stop metal shavings flying.

Here’s an easy guide to help you get everything done quickly.

  1. Make a dimple, or indent, wherever you plan to drill. Marking the area is a great way to ensure you stay on course. The indent will also help guide the drill. Mark your location with a center punch or a hammer.
  2. Use the right drill bit for the job. Check the size of the holes and use the bit that corresponds to the hole size. You need to use a drill bit slightly smaller than the screw if you are following the hole. The screw will be able to grip the metal leftovers, forming a strong bond.
  3. If the cast iron is loose, brace it in place. It will already be braced if it is connected to a solid object. Use a table vice for both sides, rather than just one.
  4. Start with a small bit to avoid making mistakes. It is better to try it several times than to mess up the whole thing.
  5. Hold the trigger and pull the drill slowly back and forth into the hole. This will deburr your hole by removing the metal debris.
  6. Use a dry cloth to wipe down the surface, followed by a wet one. Then, repeat with the dry. Do not forget the inside of the holes, even if they are thin. Metal debris is not only harmful, but also prevents screws from bonding properly.

It’s that simple!

This material is also very durable. If you use the drill bit mentioned at the start of this section, it’s malleable.

Let’s finish with a few tips that will help you do the job well.

More Tips and Advice

Security is important but so is comfort. You can have the best of both by following these tips. Try them out and see what works for you.

  • You can use extra cutting fluid while drilling. A drill bit will warm up when you are using it regularly. If you use the drill bit for a long time, wipe away any debris and reapply lubricant.
  • Use a slow speed setting . A higher speed will cause more friction and heat. You can drill through cast-iron with less heat and without damaging your bits. It is best to keep your drill speed below 1000 RPM.
  • Use a step bit if you want to bore a large hole.
  • Always keep an old rag handy when using a drill on any metal. You will have to clean up any excess cutting fluid or metal shavings. The metal shavings and cutting fluid can be dangerous if you wipe it on your shirt or pants (as some DIYers have done).
  • Mark your surface in advance with a permanent pen. This will help you know exactly where to drill.
  • Be sure to measure the width of your material before drilling. You could damage the materials behind if you drill too deep. To avoid these issues, keep a leveler and a ruler in your toolkit at all times.
  • Never drill loose cast iron. If it is not already attached, vices are a must.


Cast iron drilling is simple. Cast iron is brittle and doesn’t contain much debris.

This material is a great choice for home projects because of its heat resistance and durability. You can drill through it and use it without fear.


  • Any metal drill bit can be used to drill cast iron.
  • If you are drilling multiple holes, don’t forget the cutting fluid.
  • Use a vice or clamp when drilling into any surface.
  • Wear safety goggles and gloves.
  • Mark the area with a pen, then use a hammer and a center punch.
  • Drill slowly to avoid excessive friction, heat and dulling.

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