Vendor handoff: what goes on the print to the heat treater, nitride house, and polisher

A tool builder sends a 16-inch H13 forge die block out for vacuum heat treat. The print reads, in full, "Harden and temper to 48-50 HRC, vacuum quench, two tempers." The heat treater calls back the next morning with a print revision request. They want the austenitize temperature, the soak time per inch, the gas quench pressure, the temper temperatures and times, and the substrate certification level. The tool builder pushes back: the spec has the hardness and the cycle outline, the rest is what the heat treater is supposed to know. The heat treater refuses to quote until the print revision lands. Two weeks of lead time gone before the part has moved.

The heat treater was right. A spec that names the hardness and the medium without the parameters underneath leaves every furnace setpoint to the vendor's standard recipe. A vendor running a standard recipe produces a standard result, which on H13 in a forge die is rarely the result the part needs. The print is the contract. Anything not on the print is the vendor's discretion, and vendor discretion is where the same nominal spec becomes a 200K-cycle die at one shop and a 50K-cycle die at another.

This lesson covers the three external vendor handoffs that every forge die build crosses: heat treat, nitride, and polish. Each gets a callout template with the line items that need to be on the print and an explanation of what each line item closes off. The closing step covers what to keep off the print so the vendors do not pad scope against requirements the part does not need.