Cutting & Punching
Round Knife
A half-moon blade for long sweeping cuts, traditional and satisfying once it is sharp.
Round Knife · schematic
| Diameter | 100 mm |
|---|---|
| Overall length | 180 mm |
| Blade material | High-carbon steel |
| Edge | Single bevel |
| Handle | Two hardwood scales |
| Weight | 150 g |
| Material | Carbon steel, 59 HRC |
|---|---|
| Blade thickness | 1.2 mm |
| Suitable leather | 1 to 5 mm |
| Cutting action | Rocking push |
| Sharpening | Bevel side only |
| Compatible processes | Panel and strap cutting |
Overview
The round knife, also called a head knife or half-moon knife, is the classic saddler blade. Its curved edge lets you rock through a long straight cut or swing around a wide curve without lifting the tool. It is quick, quiet and very satisfying in experienced hands.
It is also the hardest common tool to master. The edge is exposed on both ends, the blade is heavy, and a dull round knife is genuinely dangerous because it forces you to push. Beginners often find a fixed leather knife easier to control, then return to the round knife once their sharpening is reliable.
Choose a blade of roughly 100 mm diameter in high-carbon steel, honed on the bevel side only. Keep the flat face dead flat so the knife cuts true, and store it in a sheath between sessions.
Safety
Hazard. The half-moon edge is exposed on both ends; always cut on a mat and store the knife in a sheath.
How to use it well
- Keep the flat face of the blade perfectly flat when honing so it cuts straight.
- Use a rocking motion and let the curve do the work instead of forcing the blade.
- Cut on a firm mat that lets the tip pass through without chipping the edge.
- Practise on scrap leather until the stroke feels smooth and controlled.
Compatible leathers and materials
Round Knife is suited to the following leather types. Anything outside this list is worth testing on an offcut first.
At a glance
| Category | Cutting & Punching |
|---|---|
| Stage | Cut |
| Suitable leather | Veg-Tan, Chrome-Tan, Oil-Tan |
| Beginner priority | Rank 16 of 28 |
Educational use only. Hide & Stitch is an independent, non-commercial reference. Nothing here is for sale and nothing here is a substitute for competent in-person instruction. Edged tools, dyes, solvents and adhesives can cause serious injury — read and follow the manufacturer instructions and safety data sheets, and work with ventilation and appropriate protection. Specifications are typical values for this class of tool and vary between makers.
Related
Works well with
Head Knife
The traditional saddler blade with a round end and a point for cutting and skiving.
Leather Knife
The main cutting blade for straight lines and skiving, and the first tool most makers buy.
Rotary Cutter
A roller blade for long straight cuts and light leathers, fast but easy to wander.