#20, #21 and #22 Scalpel Blades: Sizes, Handle Fit and Uses

The #20, #21 and #22 are three sizes of one shape: a big version of the #10 curved blade, all on the #4 handle. The #20 is the smallest, the #21 sits in the middle and the #22 is the largest of the three. The bigger the specimen or material, the bigger the number. None of them fit a #3 or #7 handle: for that, use a #10.

Not medical advice. We quote the maker on how surgeons use these blades only to explain the shape. Our blades are sold for craft, hobby, study, dissection and taxidermy, not as medical devices.

The #20, #21 and #22 blades at a glance

Spec	#20	#21	#22
Shape	Large version of the No. 10: curved cutting edge, flat unsharpened back	Same shape, larger than the #20 and smaller than the #22	Same shape, larger than the #20 and #21
Fitting	No. 4 range	No. 4 range	No. 4 range
Fits these handles	#4 in our store. Swann Morton lists 4, 4L, 4 Graduated and 6B.	Same as the #20	Same as the #20
Does not fit	#3 and #7 handles	#3 and #7 handles	#3 and #7 handles
Same shape, smaller	#10 on a #3 or #7 handle	#10, or the #20	#10, or the #20 and #21
Our packs	Carbon steel, 10 blades, each in its own sterile foil pouch (gamma radiation, as declared by the manufacturer)
Edge length	Not published by the maker, so we do not print one

What #20, #21 and #22 blades are used for

The curve is the same as on the #10: a long edge you draw through the cut. The extra size gives you a longer stroke through bigger or tougher material.

Job	Why a large curved blade works	Also look at
Large specimens, necropsy and anatomy labs	One long stroke covers a lot of tissue. We list the #22, #23, #20 and #21 for this, in that order.	#23
Taxidermy and skinning	Long, even cuts along a hide	#23 first, then the #22
Leather	Long cuts in thick hide	#23 on the same #4 handle

In surgery, Swann Morton says the No. 22 is “used for skin incisions in both cardiac and thoracic surgery” and the No. 20 for “orthopaedic and general surgical procedures” (Swann Morton product pages, read 11/11/2026). That is the maker’s description of clinical use, not a use we sell for.

#20 vs #21 vs #22, and #10 vs #22

The maker describes all three with the same words, and only the size changes. The #21 is described as “larger than the No.20 but smaller than the No.22”.

Blade	Size in the family	Handle	Pick it for
#10	The standard size	#3 or #7	Everyday long strokes on small to medium work
#20	Smallest of the large three	#4	Larger work where you want some control
#21	Middle	#4	The step between the two
#22	Largest of the three	#4	Big specimens and long cuts in thick material

#10 vs #22: same curved shape, but the #22 is the large version on a different fitting, so it needs a #4 handle. The #10 is for smaller jobs on a #3 or #7. If the job is skinning or thick hide, look at the #23 too. The full chart for every number is in our scalpel blade sizes guide.

Which handle fits a #20, #21 or #22 blade?

All three go on a #4 handle and nothing else we sell. They will not lock onto a #3 or #7 handle, which take the No. 3 fitting.

Have a #3 or #7 handle? Use the #10, the same shape in the smaller size. More on fittings in our scalpel handle sizes guide.

Shop #20, #21 and #22 blades

One short row per blade. You will also need the #4 handle at the end if you do not own one.

#20 blades

#21 blades

#22 blades

#4 handle

Fitting and changing a large blade safely

• Fit and remove blades with pliers or a blade remover, never your fingers. Larger blades are heavier and the edge is longer.
• Carbon steel can rust: dry the blade after use and store it dry.
• Drop used blades into a blade disposal box, never the bin.

Frequently asked questions