Biography of Paul Bos

Paul Bos, widely recognized as America's foremost heat treat authority for knife blades, got an early start learning the importance of proper heat treat. He was a 9th grader, making a set of 16 cold chisels in metal shop. When he plunged them into water to cool them off, they shattered into 32 pieces. The instructor gave him an F, and it was then that Paul was determined to learn more about this amazing process. He found that the steel he used should have been oil-quenched, not water, even though he had followed the instructor's orders.

The heat treat expert he had sought out and who became Paul's mentor was a wonderful old blacksmith from Kansas City, who ran the heat treat system for Star Heat Treat and Fishing Supplies in San Diego. So, while he was still in high school, he went to work there. His main task was making fish hooks, but his mentor taught Paul all he knew about the proper heat treat process. That was it; Paul was hooked. As he says, "I fell in love with heat treat —and it's still what I love to do."

PaulBos BioIt didn't take long for Paul to put his new-found skills to work. One of his drag-racing friends was Frank Buck (Chuck Buck's brother, who died years ago), and Frank would bring custom blades to Paul for the needed heat treat. Paul then met Frank's dad, Al, and began doing more for Buck Knives.

In 1969, Paul bought Star Heat Treat and established Certified Metal Craft, and soon they were doing virtually all the heat treat done in San Diego County. By the time he left in 1980 it was the biggest heat treat service in Southern California, doing work for such big names as as Boeing, Lockheed, Grumman and others.

At the same time, he was still working with Buck Knives. He found himself working 18 hours a day, seven days a week, and decided that was too much. So he got out!

But his love of heat treat and Buck Knives was still very much alive. In the late '70s he had helped Buck set up their own heat treat department, complete with the ovens and all the necessary equipment. So he and Buck worked out an arrangement where Paul would operate his own business right in the Buck plant - a win-win situation, where he was always on-site to serve Buck, while still doing heat treat for custom knifemakers all over America. In 2001, he actually sold his business to Buck Knives, but in effect the situation is the same - he's still their on-site heat treat expert, and he still works with the many knifemakers he's known and served for as many as 20 to 30 years. And above all, as Chuck and Paul would be the first to tell you, he's like one of the family!

What Is heat Treating?

Heat treating is the process used to impart special qualities to metals and alloys (hardness, strength, ductility, etc.). When heat and subsequent cooling are applied to metals in their solid state, the physical and structural properties (but not the chemical composition) of these metals are changed. Different metals respond to treatment at different temperatures. Each metal has a specific chemical composition, so changes in physical and structural properties take place at different, critical temperatures. Depending on the temperature used, these changes can represent a change in grain size, increase in toughness, removal of internal stresses, or formation of a hard surface on a ductile core. In addition to changes induced by heat, the rate and method of cooling have an effect on the structural properties. For example, in carbon steels, a rapid cooling will produce a metal with a hard structure, while a slow cooling will produce the opposite effect. Even small percentages of elements in the metal composition, such as carbon, will greatly determine the temperature, time, method and rate of cooling that needs to be used in the heat treating process. To achieve the desired heat treating results, it is crucial for us to know the type of metal being submitted for treatment and the desired results (Rockwell Hardness).

Our Heating Specifications

Materials Heat Treated: All stainless steels, air hardening tool steels, and stainless steel Damascus.

Blades are hardened in an inert atmosphere, cryogenically quenched to -280 degrees F and double tempered (triple tempering is available at an additional charge). Tool steels are snap tempered at 375 degrees F before cryogenic cooling. All blades are checked for straightness and 100% Rockwell tested. Maximum length for all materials is 32 inches.

Shipping Instructions

  • Clean bluing and tape residue off all blades.
  • Clean grinding and buffing compounds from blades and out of any holes.
  • Clean burrs from holes.
  • Make sure blades are straight.
  • Do NOT tape blades together. Instead, roll 4 or 5 blades in double newspaper with tangs out so points of blades do not stick through other end. Then tape around paper.
  • Pack in sturdy box with wadded-up newspapers to make sure blades will not move around.PLEASE DO NOT USE PACKING PEANUTS.

Make sure you put a note in the box with the following REQUIRED INFORMATION:

  • Your name, shipping and billing addresses, phone number and email address.
  • Quantity of blades enclosed.
  • Materials blades are made of.
  • Rockwell Hardness desired.
  • How do you want blades shipped back? (Ground, Air, Overnight?)
  • When shipping back, do you want blades insured? For how much?
  • If possible, please vibro etch your name and blade material onto blade tang.

On your address label to us, do not put "custom knives". Put just your name and address. This will help minimize the possibility of theft.

Ship package to:
Paul Bos Heat Treating
660 S. Lochsa Street
Post Falls, ID 83854-5200

Order fulfillment usually takes about 5-8 working days of shop time after receiving blades.

When completed, we ship your blades to you via UPS ground unless otherwise specified.

For Christmas or Shows, please plan ahead.

**Note: The shop is closed 2 weeks for Christmas and 2 weeks in July or August. Please contact us regarding your order fulfillment during these times.

Questions? Call us: (208) 262-0500, ext. 211 or email:


Minimum Charge

  • Heat treating up to 20 blades: $85.00
  • Each blade over 20: $4.25
  • Mixed Materials: $10.00

Single Blades

  • Each blade, minimum charge of $17.00


  • Triple tempering: additional $15.00
  • Folder springs and folder parts tempered back to spring temper: $1.50 each

Additional Charges

  • Blades over 10 inches long: $0.50 per each additional inch
  • Mixed batches of materials (will advise)
  • Extensive cleaning or straightening before heat treating: $50.00 per hour of labor


  • Packaging charge: $5.00 per package


  • Shipping charges will be assessed based on your preference: (air, ground or overnight)


  • Payment is not required in advance, but is due upon receipt of invoice. A $5.00 service charge will be applied to any payments not received in 30 days.