Marking Knife Blade cutting?

[Wooden Mechanic]

Hi all,

Don't exactly know where this should be place, please move accordingly if need be.

I am after a company that can manufacture approximately 50-100 marking knife blades for a production project. I would like to get them as accurate as possible, takes the guess work out of producing symmetrical blades.

They will be cut from a single sheet of tool steel (Can we buy sheets?) ~4-5mm thick without the bevels on them. I would love to get them cut with the bevels ground but I am willing to put in the effort and do that myself.

My questions are;

Does anyone know of a company that would be interested in doing the job in Perth?

What would be a suitable tool steel to get the blades made from? Something that holds an edge well but can be ground easily by myself.

Alternatively would it be plausible to just buy them from Czech Hand Tool works? Only about $35 per blade.

Many thanks,
Harlan

[thumbsucker]

You are barking up a path that I have walked down few times now.

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All my contact are in Melbourne so I do not know of 3rd party suppliers in WA.

However I can advice on other aspects.

Your best place to get steel sheet is Bohler, they have a outlet at 29-33 Gauge Circuit Canning Vale Perth W.A 6155. A 4.5 mm sheet will set you back about $2500 plus gst. Your tool steel choices in sheet are A2, D2, and M2. Tool steel is a slippery slope of learning. For a marking knives A2 would be fine.

You will get a whole lot more then 100 marking knives from a sheet a sheet is usually 1500 x 800 mm, depending on the size of the knife, at a rough guess you could be looking at up to 500 marking knives from a sheet. You can get it laser cut, it is relatively cheap if you are getting 500 knives cut. Expect to pay about $3 per knife. The less knives the more you pay, you are actually paying for programing and setup cost. You will need to supply a CAD file.

You will need to get the blades heat treated (As you cannot buy tool steel that has been heat treated of the shelf, easily, Mjing however sells small HSS bars that you could grind, like here). Heat treating is cheap and is charged by the kg. Expect to pay anything from $12 - $25 per kg. A Sheet that thick weights about 60 kg's so that comes to about $700 to $1000.

You then need them surface ground this is the most expensive process, expect to pay about $15 per marking knife, that comes out to $7500 for 500 knives. You could do it with a linisher but it would be a pain.

In short it not a simple process to do it yourself.

Your other option is to search the yellow pages and look for industrial knife makers. They have the option to do much of the stuff in house, however you will pay a premium, since you are asking for such a small job.

Your best approach is to buy O1 tool steel in ground bar. Then cut it up with a hack saw shape it on the grinder. The heat treat with an lpg torch, then flatten. There are lots of articles on working O1 tool steel.

My final point is that 5 mm is way to thick for a marking knife. Most knives are +/-2 mm thick. Anything thicker and it becomes a problem getting into tight places. I have done a study of commercial knife makers, I drew up a CAD file to distill my thoughts.

[Wooden Mechanic]

Woah!!!

I knew it would be a lot but not that much. Thank you for all the info Thumbsucker, is greatly appreciated.

Guess I will need to ponder on another option. Could be more feasible to by bar stock and cut them and shape them myself.

Hmmmmm, got lots of thinking to do.

Thanks again,
Harlan