Hardy hole sizes by anvil weight
Quick answer
The hardy hole is the square hole in an anvil's heel that holds bottom tools; the pritchel is the smaller round hole used for punching. Hardy sizes scale with anvil weight - roughly 5/8-3/4 in on small anvils (55-100 lb), 1 in on 100-200 lb anvils, and 1-1/4 in or more on big ones. Buy hardy tools whose shank matches, or bush a slightly small one.
Every bottom tool a blacksmith drops into the anvil - hot cuts, fullers, bicks, bending forks - is sized to the hardy hole, the square hole near the heel. Get the size wrong and the tool rocks, sits loose, or will not seat at all. This reference lists the typical hardy hole size for each anvil weight class so you can buy tooling that fits, and explains the smaller round pritchel hole next to it.
| Anvil weight | Hardy hole (square) | Pritchel hole (round) | Notes |
|---|---|---|---|
| 55-70 lb | 5/8-3/4 in | ~3/8 in | Light tools; small selection off the shelf |
| 70-100 lb | 3/4 in | 3/8-1/2 in | The most common beginner size |
| 100-150 lb | 3/4-1 in | 1/2 in | Widest tool availability |
| 150-200 lb | 1 in | 1/2-5/8 in | 1 in is the de-facto standard size |
| 200 lb and up | 1-1/4 in and up | 5/8 in | Big anvils; heavy hardy tooling |
Not sure how much anvil you need? Size it here
Hardy hole vs pritchel hole
Two holes sit in the heel of a London-pattern anvil and they do different jobs:
- The hardy hole is square. It holds hardy (bottom) tools by their square shank and takes the sideways force of cutting, fullering and bending.
- The pritchel hole is round and smaller. It is a clearance hole for punching - you punch hot stock over it so the slug and the punch have somewhere to go, and it helps with light bending and riveting.
Do not force a round punch into the square hardy hole or drive tooling into the pritchel - each has its purpose. If you are still choosing an anvil, the best beginner anvil guide covers which weight and features to look for.
Hardy tools that drop into the hole
Match the shank to your measured hardy hole before buying. A common 1 in hole fits the widest selection.
Hardy-hole fuller tool
1 in shank
- Material
- Forged Steel
- Hardy hole
- 1 in
Drops into the hardy hole to isolate and draw out stock fast. Match the shank to your anvil's hardy hole size before buying.
Hot-cut hardy tool
1 in shank
- Material
- Forged Steel
- Hardy hole
- 1 in
An anvil-mounted chisel for cutting hot stock to length. Keep hot steel off the edge when not cutting so it stays sharp.
How to measure and adapt
Measure across the flats of the square hole with calipers or a steel rule - the size is the width of the square, not the diagonal. If a hardy tool's shank is slightly undersized, wrap the shank in a wrap of steel shim or forge a light upset shoulder so it seats without rocking; if it is slightly oversized, you can grind or file the shank down, never the anvil. A shank that is very far off is the wrong tool - return it.
Making your own hardy tools is a great way to get a perfect fit: forge the shank to your exact hole and it will never rattle. The hardy tools guide walks through which to make first, and the hammer types reference helps you pick the striking tools to pair with them.
Frequently asked questions
What size is a standard hardy hole?
There is no single standard, but 1 inch is the most common size on 150-200 lb anvils and has the widest tool selection. Smaller beginner anvils (55-100 lb) usually have a 5/8 to 3/4 inch hardy hole, and large anvils run 1-1/4 inch or more. Hardy holes vary by maker and country, so always measure across the flats of your own anvil before buying tooling.
What is the difference between the hardy hole and the pritchel hole?
The hardy hole is the square hole that holds bottom tools such as hot cuts and fullers and takes sideways cutting force. The pritchel hole is the smaller round hole used mainly as clearance when punching hot steel, plus light bending and riveting. Use the square hole for square-shanked tools and the round hole for punching - they are not interchangeable.
What if my hardy tool does not fit the hole?
If the shank is a little too small, shim it with steel or forge a light shoulder so it seats without rocking; if it is a little too big, grind or file the shank down - never modify the anvil's hole. A tool that is far off the size is simply the wrong tool for your anvil, so check the shank size against your measured hole before you buy.
Can I make my own hardy tools?
Yes, and it is one of the best beginner projects because you can forge the shank to fit your hole exactly for a rattle-free seat. Start with a hot cut or a simple fuller from tool steel or a suitable scrap, size the square shank to your hardy hole, and harden the working end. See our hardy tools guide for which tools to make first.
Last verified 2026-06. Specs, sizes and market prices change - confirm details on the retailer page before buying.