Best: a drawing, even a bad one
A dimensioned sketch on paper, photographed with a phone, is enough to quote from. Mark the outer diameter, bore, thickness and edge angle for round knives; length, width, thickness, hole positions and edge angle for straight knives. We redraw it properly and send the clean drawing back for your written confirmation before any steel is cut.
Almost as good: the old blade
A worn blade tells us more than a perfect drawing: the wear pattern shows the real cutting angle, the chips show the shocks, and we can measure every dimension on our granite plate. One used blade, sent by courier, removes every guess. Mark on it which side faced the material if you can.
Minimum: a photo with a ruler
Lay the blade flat, put a steel ruler or caliper across it, shoot straight down with your phone. One photo of the whole blade, one close-up of the edge, one of any holes or slots. Add three facts in the message: what you cut, how thick, and how the old blade died. That is a complete enquiry.
What happens next
Within one working day you get a reply: the steel grade we recommend and why, the hardness window, the price, and the lead time as it actually stands that week. If your geometry has a known weak point — an edge angle too fine for the material, a hole too close to the edge — we say so on the first reply, not after the blade fails.
Seeing this problem on your line? Send a photo of the old blade or your drawing — one working day for an answer.