As a shop that has worked with knife makers for over a decade, we know choosing materials and finishes are some of the most important decisions when it comes to planning your knife. In this article, we want to address some common questions we get from clients about raw materials and surface conditions for custom knife projects.
What Raw Materials Are Available?
We can order the material from our suppliers, listed here. Or you can drop ship materials to us; we do not accept customer provided remnants.
If we are ordering material for you, let us know if you want it pre-ground (blanchard ground--see surface condition examples below) or oversize stock as rolled from the mill (which will require finishing for thickness later).
Material Sizes:
The size of the raw material is important because it determines the yield of parts. After you have started an order with us and your designs have been approved for cutting, we will input your design into our nesting software to determine exactly how many parts will fit the most efficiently on a certain size sheet.
CPM blade steel and titanium standard length and width sheet size is 22-25" x 36"
CPM blade steel and titanium (hot rolled) is rolled oversize thickness for cleanup (see table below) -- supplied by Niagra Specialty Metals
Listed size | Actual thickness range for hot rolled |
3/32"= .094" | .103"/.133" |
1/8"= .125" | .140"/.156" |
5/32"= .157" | .172"/.188" |
3/16"= .188" | .207"/.227" |
1/4"= .25" | .275"/.300" |
Want to estimate your material yield before ordering?
1. Determine sheet size
2. Add a .125" margin around your design
3. Lay it out on cardboard the same size as your material and trace the design
Or if you are using CAD software-use a .125" margin at any pinch points
This will give you a rough estimate of about how many pieces will fit. With our software and precise machining, we can get better material utilization than if you were cutting blanks out of bar stock by hand.
Cold Rolled vs. Hot Rolled
Hot rolled is rolled oversize thickness (see chart above) for additional finishing. We recommend double disc grinding, but it can be used as rolled for low volume orders with the understanding that it will take additional machining to finish.
Cold rolled is rolled at nominal thicknesses and it requires less cleanup to finish. It can also be double disc ground to assure it is a certain thickness, flat, and parallel.
(Left to right--all Ti 6-4 GD 5)
1. Cold rolled/Double Disc Ground/CNC Milled, 2. Cold rolled/shape cut, 3. Hot rolled/CNC Mill
Examples of Surface Conditions/ Finishes:
Below are some examples of surface finishes in process. It is up to our customers to do final finishing or to let us know how they would like it finished by us.
Any required surface finishes must be called out before the quote.
Check our Secondary Operations page for a list of options to add to your order.
Vibratory Tumble Deburr in Ceramic Media after Cutting
Double Disc Ground Titanium Liners
Rough Surface Ground to Remove Decarb -- Ready for Final Thickness Grinding
Surface Ground Flats and Bevel Ground by hand @ Doyle Knives
Post Heat Treat Blanchard Ground
Post Heat Treat Blanchard Ground Handle with Bevel Ground Blade
Lapping for very tight tolerances of flatness, parallelism, or thickness
Warpage:
Another thing to consider is the residual stress in raw material from the manufacturing at the rolling mill and secondary operations. Some materials will have a greater chance of warpage due to stress relief when parts are being cut from the sheet.
Straightening is common and is usually addressed pre heat-treat and during the heat-treating process and must be included in the quote if you want your parts straightened.
If you have any questions about raw materials/surface conditions for custom knife projects or are ready to place and order, contact us today!
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