How to Fit Knife Bolsters Correctly

How to Fit Knife Bolsters Correctly

A quick step-by-step tutorial on how to fit and peen bolsters onto your handmade knives.

Step 1: Mark off the bolsters slightly bigger than needed and cut them out.

Step 2: Flatten the insides (Blade side) of the bolster.

Decide if you are going to make the back of the bolster square or dovetailed (Sketch 1 below). Please note that if you decide to do a dovetail, the back of the bolster needs to be slightly longer. This is important to ensure that when you peen the rivets, the back of the bolster does not bulge out (Sketch 2 below).

I always ensure that the closest edge of the back of the bolster is at least 4,8mm from the back of the rivet. Also, note that I use 1,6mm pins. If your pins are thicker, you need to increase this distance.

BolsterFittingTut Sketch1and2 How to Fit Knife Bolsters Correctly 1

Position the bolster on the blade, so that the back of the bolster is in the correct position with relation to the holes in the blade, as described in Step 3. Clamp the bolster to the blade with locking pliers (Visegrip) or drill clamps. Then, using the hole in the blade as a guide, drill the holes through the bolster (Sketch 3 below).

After each hole is drilled, place a pin of the same diameter as your rivet in each hole, to ensure that the bolster does not move.

BolsterFittingTut Sketch3 How to Fit Knife Bolsters Correctly 2

Step 5: After drilling all the holes, remove the bolster, countersink the hole on the blade side of the bolster and make sure it is still flat.

Step 6: Now place the 2 bolsters together, ensuring that the backsides are perfectly aligned, and then clamp the bolsters together with locking pliers. You can add a drop of superglue to the front of the bolsters to ensure they don’t move when during drilling. Now with the first bolster as your drill guide repeat the previous 2 steps. Remember to put the pins in the holes as you go along.

Step 7: Fit the bolsters on the blade, one at a time, and mark off the outside of the blade onto the bolsters with a scribe (Sketch 4 below). Remove the bolsters and mark the front edge of the bolsters.

Remember that the same principle applies to the back of the bolster. Leave about 4mm between the front of the bolster and the rivets.

BolsterFittingTut Sketch4 How to Fit Knife Bolsters Correctly 3

Step 8: Cut or grind the bolsters as close to the scribed lines as possible.

Step 9: Fit both bolsters on the blade with pins. Then grind the outer edges of the bolsters down until the belt just starts touching the edge of the tang.

Remove the bolsters from the blade and remove all the burs.

Step 10: Grind the front of at least 1of the bolsters up to the scribed line. Now fit the 2 bolsters together with the pins in place and clamp them with locking pliers or a G-clamp.

Step 11: Grind and polish the front faces of the bolsters. This is the final finish on the front of the bolster.

Now for final fitment. Make sure the inside of the bolsters are perfectly flat. Fit them onto the blade, with the rivets cut so that they stick out about 1,5mm to 2mm on each side of the bolster.

Step 12: Place on a sturdy anvil and using a ball-peen hammer, peen the back rivets, alternating the sides, until you can see that bolster starting to bulge around the rivet (Sketch 7 below). Now grind the bolsters taper, so that they taper towards the blade. Then peen the front rivets in the same way as the back ones (Sketch 7.2 below).

Once all the rivets are set, give them all a couple of good blows with the hammer to make sure they are secure.

BolsterFittingTut Sketch7 How to Fit Knife Bolsters Correctly 4

Additional Notes: Make sure that you use rivet pin material that will blend in with the bolster material. If you are using Brass or Bronze try to get the same grade for your rivets.

I mostly use 303 or 304 Stainless steel bolsters (visit the store to purchase).
For the 303 bolsters, I use 316L rivets and for 304 I use 308 or 309 rivets. This will help you to “hide” the rivets.

Now you can fit the handle slabs!!

BolsterFittingTut Sketchfinal How to Fit Knife Bolsters Correctly 5

Updated October 2020

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