How To Choose and Fit a Knife Blade

To ensure you get the best from your knife, it's worth putting some thought into which blade will suit you best. Moreover, how to actually get it fitted into the handle!

This short set of instructions is intended for purchasers of one of my custom marking knife handles, and/or potential customers who want to know a little bit more about them before purchasing. Keep in mind that I make these knives in batches, although the high demand often means they are out of stock. So if you are interested in purchasing one, be sure to sign up for Marking Knife Notifications here.

Which Blade to Choose?

The first thing you need to decide is which blade you want to fit into the handle. The handle is made to fit the Swann Morton ‘SM' range of blades which come in a variety of sizes. It's also possible to fit the Stanley Pocket Knife blade into the tool. However it's important you do not over-tighten this as the blade fitting is slightly different and may chip or snap within the slot.

Swann-Morton SM01

This is the blade that I recommend 99% of the time. It's chisel-like cross section makes it a very intuitive blade to use.

Swann-Morton SM02

Same as the SM03 blade, but calls for a much steeper angle of attack when using the point of the blade

Swann-Morton SM03

If you are moving across from a more traditional marking knife, this blade shape may be more familiar to you.

Swann-Morton SM014

I like to use these to open boxes, that's about it. These are not suitable to run against the edge of a ruler.

Swann-Morton SM03B

I am currently experimenting with these to see if there is any noticeable benefit over the standard SM03

Swann-Morton SM01B

I am currently experimenting with these to see if there is any noticeable benefit over the standard SM01

How To Fit Your Blade

The slots on the marking knives are cut to incredibly fine tolerances and occasionally vary in snugness around the blade. This variation occurs when the grub screw hole is being drilled and tapped as some swarf may breakout into the slot. This is not a huge issue and will eventually wear away once the blade has been removed and replaced a few times. Each knife is individually tested before packaging to ensure the blade can be easily changed.

If your blade is too snug to safely insert by hand. There are two techniques you can use to insert the blade. With both of these methods, ensure eye protection is worn in case the blade breaks.

The first technique involves the use of a mechanics/engineers vice. Simply clamp the sharp part of the blade within the jaws so it is out of harms way. Then carefully press the handle into position. As long as your vice jaws do not have heavily corrugated surfaces (usually for grip) the jaws will not damage the sharp points as this is a double bevel knife.

The second technique involves pressing the knife into a soft surface. So I usually use the end of my workbench for this.

To start with, push the blade in as far is it will go by hand. Then press the blade into a veritcal surface with the sharp edge pointing downward. Sight down the top of the blade to ensure it isn't bending sideways, and carefully wiggle the handle up and down. This will ‘walk' your blade into the bottom of the slot.

To ensure your blade has bottomed out. Firstly, check that the keyhole slot on the blade is completely submerged in the ferrule and is not longer visible. Secondly, remove the grub screw and check that the hole in the blade lines up with the grub screw thread. Both the blade hole and the screw thread are exactly the same diameter so you should be able to see straight through it. If it is misaligned, the blade may chip when the grub screw is tightened which will result in difficult to remove debris within the slot.

Tightening

It's very important that you do not over tighten the grub screw as this can either chip the blade or strip the thread. Neither of which are covered by my Warranty. I advise using the long end of the allen key to tighten the grub screw as it prevents you from applying too much torque. Use the short end of the allen key to loosen the grub screw when removing the blade if it is too tight.

Removing

Please exercise precaution when removing the blades by hand, even if the blade can easily be removed without mechanical assistance. It is therefore recommened you use cut proof gloves for this step just incase you slip while gripping the blade. If the blade is too tight to remove by hand, there are two different steps you can follow.

Firstly, you can use a mechanics/engineers vice to do the reverse of what was described when fitting the blade. Simply clamp the blade as far into the jaws as possible, and wiggle the handle up and down while pulling up. Ensure the blade does not bend side to side when doing this!

Alternatively, you can use pliers to safely remove the blade. Simply grip the blade at the widest point using the pliers, and grip the handle with a full fist in the other hand. Carefully pull them apart while ensuring the blade does not bend side to side.

Please do not use this method to insert the blade as this will involve you pushing your hands together (toward the sharp point of the blade) Reserve using pliers for blade removal only.

How To Care For Your Marking Knife

Want your knife to look brand new every time you use it? This guide details everything you need to know from refinishing, to maintaining the blade slot.

One Comment

  • Any chance you will be doing these handles again soon? I tried to use the notification link but It appears broken.

    Reply

Leave a Reply

Your email address will not be published.

14 + seventeen =

Download My

Free eBook!

Simply enter your details below to unlock the hidden potential in your workbench.

(Book will be sent to your email inbox)

%d bloggers like this: