Peterson Welding Laboratory, Inc. (also known as Peterson Welding Laboratories, Inc. and Peterson Welding Labs, Inc.) was established by Roy Peterson. Peterson died in 1946 and the business passed to son Delmont R. Peterson. The business specialized in welding engine blocks and heads, and by 1946 they were manufacturing a specialized surface grinder for flattening warped heads, blocks and manifolds. This grinder has the grinding wheel mounted flat and flush with the surface of a table.

In 1958 the company relocated from Kansas City, MO, to Merriam, KS, and changed its name to Peterson Machine Tool, Inc. Under that name the company survived until at least 1979.

Information Sources

• 1946 issue of Welding Engineer lists "Peterson Welding Lab, 1423 Virginia, Kansas City 6 Mo" as a maker of abrasive grinders. Another mention from the same year: "D. R. Peterson, son of the late Roy Peterson, has been appointed president of Peterson Welding Laboratories, Kansas City, Mo."
• 1948 issue of Industrial Marketing.

  Peterson Welding Laboratories didn't both much with layout or typography, but the headline is a pip: 'Collect $3 for This 10 Minute Job on the New Peterson Surface Grinder.' In addition to a listing of product features, there is this hard-selling copy: A new money-making service for the auto machine shop, grinding all warped car, truck and tractor cylinder heads, blocks and manifolds. Only 3 jobs a day pay for your Peterson Grinder in 40 days. Some shop owners report their Peterson Grinder paid for itself in first 30 days.

  This new fast-cutting grinding wheel mounted level level with table top enables any unskilled operator to do a fast accurate job, grinding to .001 inch without set-up. Tiptoe control enables operator's foot to raise grinding wheel to cutting level, leaving hands free for work.

  17-inch suction fan turning 17,500 RPM under grinding wheel hub deposits injurious dust and grindings in two dust collectors."

  OK as inserted. This good, practical copy came from the typewriter keys of JOHN C. HARVEY, account executive, BARROWS ADVERTISING COMPANY, and D. R. PETERSON , PETERSON WELDING LABORATORIES, Kansas City, Mo.

• 1948 Proceedings of the Annual Convention of the International Acetylene Association" lists attendees, including "Peterson, D. R. / Peterson Welding Lab / Kansas City, Mo."
• 1949 Official Gazette of the United States Patent Office, copyright Ser. No. 578,463 for a logo with the text "VIBRA-MOTIVE" in a 45-degree arc. "Delmont R. Peterson, doing business as Peterson Welding Laboratories, Kansas City, Mo. Filed May 9, 1949. The term "Motive" is disclaimed. For Electrically Powered Table Type Vibratory Grinding Machines. Claims use since Mar. 7, 1949."
• 1950 issue of Western Trucking and Motor Transportation. "Peterson Welding Company demonstrated for the first time its new Peterson-Burston screw-in valve seat, which is said to..."
• February 1952 Trucking News.

  Peterson Explains Effect of Heat on Cylinder Block

  Speaking before the January 8th meeting of the Equipment and Maintenance Division of the Michigan Trucking Association in the Hotel Fort Shelby, D. R. Peterson of the Peterson Welding Laboratories, Inc., Kansas City. Mo., stated that 9 out of 10 cylinder head cracks occur above cylinders No. 2, 3, 4 and 5. The meeting, expressing by an attendance of 88 members and guests, their keen interest in one of what is termed the most important maintenance problems confronting the motor fleets today, paid strict attention to Mr. Peterson's remarks and asked many pointed questions in an open discussion.

  "You will find also," said Mr. Peterson, that 9 out of 10 of valve failures occur in the same cylinders, 2, 3, 4, and 5. It is our belief that this is caused by the hot spot created between the No. 2 and 3 exhaust ports and another hot spot created between the 4 and 5 ports. This causes such distortion that eventually the valves burn or the head cracks. Cylinders 1 and 6 each has its individual port.

  "My father, Roy Peterson, started Peterson Welding Laboratories...

  "One of the most important facts derived from this study was the effect of heat on the different thicknesses of metal in the complicated structures of a cylinder block and cylinder head. On the thousands of heads that we welded, we observed that the cracks almost always occurred in the same place, which no doubt was its weakest point.

  "As you all know, the hottest point in your engine is the valve and valve seat, and the constant expansion and contraction causes the material to fatigue and crack at the weakest point. On many minor cracks, we were successful in lacing up the crack with tapered threaded pins. So, naturally we had always unconsciously been looking for something such as our tapered pins that would stress-relieve this hot point.

  "And today, we have found the answer—a valve seat insert that does not exert any radial pressure even under terrific heat, does not distort but stays round, and cools the valve evenly around the circumference of the head of the valve — a threaded-in seat with expansion clearance.<.p>

  "This seat was discovered at the Canadian Automotive Show three years ago. I was amazed to find that the big percentage of truck engines and industrial engines in Central Canada were using this screw-in insert. In fact, most of the Number 1 factory branches of U. S. truck manufacturers in Toronto were using this seat exclusively for replacement valve seat inserts. The Highway Department had purchased its own installation equipment and had been installing it for years.

  "Large truck lines such as Denver Chicago and Associated Transport Division of Brown Equipment and many others have experienced a terrific saving in down time caused by premature valve failure and valve port cracks.

  "Years ago the service men in the field realized the importance of valve seat height and spring tension and made cast iron inserts and installed them with relative success.

  "But as compression ratio went up, the extra heat caused these inserts to buckle and distort and lose contact with the counterbore—thus causing the valve to burn and the seat to burn as the cast iron insert surrounded by carbon couldn't transfer its heat to the water. So naturally, they tried insert material that was more resistant to heat. But at the same time, this heat resistant material was also harder. Most people today think a hard seat is the best, where actually the main benefit is that the material does not burn as easily. However, this material expands more than the cast iron in the cylinder head around it and actually buckled, cocked and distorted more than the old cast iron pressed-in ring. The average mechanic thought the seat was all right because it didn't look burnt. However, these cocked, distorted seats were causing more valve burning and breakage. The mechanic that ground these valve seat inserts noticed the stone only touched at one or two high points. If this insert is egg shaped on the inside, it is just as egg shaped on the outside and certainly not solid in the counter-bore, transferring heat as it should."

  "Inasmuch as we were already manufacturing and selling cylinder resurfacers to the engine rebuilders throughout the county and head welding equipment to many of the cylinder head reconditioning shops, we were successful in obtaining this valve seat and installation equipment rights in the United States. In the past two years we have set up and trained master shops to install these seats in all major cities.

• A search on "Peterson Welding Labs" reveal that this was a fairly common version of the name, with data points spanning 1946 to '60.
• 1955 Diesel Power lists "Peterson Welding Lab / 1423 Virginia / Kansas City 6, Mo." was providers of valve seat grinders.
• 1958-05-01 Automotive and Aviation Manufacturing. "Peterson Machine Tool, Inc. is the new name of Peterson Welding Lab., Inc., relocated at 6200 Merriam Road, Merriam, Kansas."
• We found 14 patents assigned to Peterson Machine Tool, Inc., spanning 1965 to 1978. Patents were obtained for USA, Canada, Argentina, Brazil, Italy, and Spain. A search for patents assigned to Peterson Welding came up dry.
• 2006 obituary for Delmont R. Peterson from the Kansas City Star. "Delmont R. Peterson, born in 1918, was an innovator, CEO and Chairman of the Board of Peterson Machine Tool Inc., lifelong athlete, husband, father, grandfather, and most of all a great friend/partner. 'Monty' to friends, 'Pete' in business settings, could walk into any business, restaurant,..."