Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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Knifemaker / Craftsman / Service Provider
- Joined
- Aug 20, 2004
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There have been many threads about how to drill the hole in a hidden tang handle, or make a mortice tang handle, but I don't recall many (if any) threads about shaping the tang itself. I had a question sent to me by a member about this subject and though it might be a good topic of discussion.
This is my basic opinion/preference for hidden tang shape and size:
Tapering the tang width is a good practice.
On most hidden tang knife blades, 1/2" at the shoulder and 1/4" at the end will be plenty strong. That is pretty much what I use on most knives. If the tang has less taper it's OK. Tapering and especially rounding the end help with fitting into the hole drilled in the handle. On stag handles, making the tang hole is not much of an issue and any taper or shaping of the tang is probably only necessary to match the curve of the antler.
Tapering the tang thickness IS necessary. It is needed to get the guard or bolster slot to fit properly at the shoulder.
Because the blade is ground a great amount in shaping and sanding the bevels and edge, the blade will end up thinner than the unfinished tang. After the blade is shaped and ready for HT, taper the tang thickness so it is thickest at the shoulders.
I taper the tang thickness about 25%. The last 1/4" of the tang at the shoulders has no thickness taper (or very little) so the guard will fit snug later on. After HT there will be little needed to be done to the tang to get a good fit of the guard.
TIP - Don't File the guard slot to fit the tang until after HT and final sanding. If you do it when shaping the blade pre-HT it will usually be too loose after the blade is finished and you are ready to mount the guard and handle.
As for tang length, a hidden tang should be between 75% and 100% of the blade length. On a 3" to 5" blade, a 3" to 4" tang is good.
The tang should insert 50% to 75% the length of the handle, depending on how strong the handle material is. Stag is very strong and 4" is plenty regardless of the handle length. Composites and acrylics are less strong, and the tang should be at least 75% the handle length.
On multi-piece handles that are composed of sections of different woods/materials - the tang MUST extend at least 50% into the last segment.
As a general design rule, a hidden tang at the shoulder should be 50% to 75% of the blade width at the shoulder. I tend to use around 60%, which gives me plenty of shoulder to seat against the guard/bolster and a strong tang. Obviously, blade size and style change the tang proportions, but less that 50% is getting risky for strength. A hidden tang more than 75% the handle width may end up breaking the handle with hard use.
One thing that many newer makers do wrong is make the shoulder at the ricasso a 90° angle. It should have a radiused corner at the shoulder transition. This is because a 90° transition is a stress riser and can lead to the blade breaking off right at the handle. This is most likely on thinner and smaller blades, but even a Bowie is susceptible to breaking at the handle with a hard blow or twist.
A good way to get a radiused corner is to drill a hole next to the junction of the tang-shoulder lines and then cut to the hole with your hacksaw/bandsaw. A few file strokes and the shoulder now has a perfect radiused corner. Depending on the blade size, a 1/8" to 1/4" drill bit is what I use. Position the bit so the hole lies with the perimeter of the circle on the lines you draw in the profile. Many mistakenly drill it centered on the junction of the tang and shoulders, which requires thinning the tang and moving the shoulders forward a tad to get the lines straight again.
If a pin will be used to secure the tang in the handle, drilling the tang hole pre-finishing stages is a bad idea. Once the blade is finished and the handle shaped to the final degree, the holes may not line up. It is fine to drill the hole in the handle at any stage in shaping it but leave the tang alone until you are ready for glue-up. Once all is ready, blacken the tang with a marker or Dy-Chem and place in the handle. Use a drill to mark the spot where the hole will be. Remove the blade and drill the tang with a carbide bit if the tang is filly hardened.
TIP- Make the tang hole a little larger than the pin. It will allow some play in clamping and gluing. The glue will fill the gaps and it will never come loose. I generally drill the hole through the tang about 50% larger than the pin.
Hopefully, others will chime in with their tips and comments on tangs and such.
This is my basic opinion/preference for hidden tang shape and size:
Tapering the tang width is a good practice.
On most hidden tang knife blades, 1/2" at the shoulder and 1/4" at the end will be plenty strong. That is pretty much what I use on most knives. If the tang has less taper it's OK. Tapering and especially rounding the end help with fitting into the hole drilled in the handle. On stag handles, making the tang hole is not much of an issue and any taper or shaping of the tang is probably only necessary to match the curve of the antler.
Tapering the tang thickness IS necessary. It is needed to get the guard or bolster slot to fit properly at the shoulder.
Because the blade is ground a great amount in shaping and sanding the bevels and edge, the blade will end up thinner than the unfinished tang. After the blade is shaped and ready for HT, taper the tang thickness so it is thickest at the shoulders.
I taper the tang thickness about 25%. The last 1/4" of the tang at the shoulders has no thickness taper (or very little) so the guard will fit snug later on. After HT there will be little needed to be done to the tang to get a good fit of the guard.
TIP - Don't File the guard slot to fit the tang until after HT and final sanding. If you do it when shaping the blade pre-HT it will usually be too loose after the blade is finished and you are ready to mount the guard and handle.
As for tang length, a hidden tang should be between 75% and 100% of the blade length. On a 3" to 5" blade, a 3" to 4" tang is good.
The tang should insert 50% to 75% the length of the handle, depending on how strong the handle material is. Stag is very strong and 4" is plenty regardless of the handle length. Composites and acrylics are less strong, and the tang should be at least 75% the handle length.
On multi-piece handles that are composed of sections of different woods/materials - the tang MUST extend at least 50% into the last segment.
As a general design rule, a hidden tang at the shoulder should be 50% to 75% of the blade width at the shoulder. I tend to use around 60%, which gives me plenty of shoulder to seat against the guard/bolster and a strong tang. Obviously, blade size and style change the tang proportions, but less that 50% is getting risky for strength. A hidden tang more than 75% the handle width may end up breaking the handle with hard use.
One thing that many newer makers do wrong is make the shoulder at the ricasso a 90° angle. It should have a radiused corner at the shoulder transition. This is because a 90° transition is a stress riser and can lead to the blade breaking off right at the handle. This is most likely on thinner and smaller blades, but even a Bowie is susceptible to breaking at the handle with a hard blow or twist.
A good way to get a radiused corner is to drill a hole next to the junction of the tang-shoulder lines and then cut to the hole with your hacksaw/bandsaw. A few file strokes and the shoulder now has a perfect radiused corner. Depending on the blade size, a 1/8" to 1/4" drill bit is what I use. Position the bit so the hole lies with the perimeter of the circle on the lines you draw in the profile. Many mistakenly drill it centered on the junction of the tang and shoulders, which requires thinning the tang and moving the shoulders forward a tad to get the lines straight again.
If a pin will be used to secure the tang in the handle, drilling the tang hole pre-finishing stages is a bad idea. Once the blade is finished and the handle shaped to the final degree, the holes may not line up. It is fine to drill the hole in the handle at any stage in shaping it but leave the tang alone until you are ready for glue-up. Once all is ready, blacken the tang with a marker or Dy-Chem and place in the handle. Use a drill to mark the spot where the hole will be. Remove the blade and drill the tang with a carbide bit if the tang is filly hardened.
TIP- Make the tang hole a little larger than the pin. It will allow some play in clamping and gluing. The glue will fill the gaps and it will never come loose. I generally drill the hole through the tang about 50% larger than the pin.
Hopefully, others will chime in with their tips and comments on tangs and such.
