Flame Hardening Offers an Economical Way to
Selectively Surface Harden Your Parts to
Increase Wear Resistance and Longevity!

Since 1968, Penna Flame Industries has been in the business of flame hardening steel. Each flame hardening order is assigned a unique operating procedure developed by combining metallurgical study with over 50 years of practical experience. Our flame hardening technique and traceability are unparalleled and we promise the highest level of quality to each and every customer. Quality is what we demand because quality is what our customers deserve.

Our primary methods of flame hardening steel can essentially be broken down into three categories: Spin Flame Hardening, Progressive Flame Hardening, and Progressive Spin Flame Hardening.


Here is How You Benefit

  • Increased Wear Resistence
  • Higher Hardness and Longer Life
  • Less Processing Time
  • Higher Efficiency and Productivity
  • Maintain Tensile Strength

Offering Three Flame Hardening Processes
to Meet Your Specific Applications:


Spin Flame Hardening

Spin flame hardening is a method by which a part is rotated while flame is applied to the desired area. Upon reaching a target temperature, the part is immersed in a quench bath. During the process the temperature of the part is monitored with the use of pyrometers and/or a thermal imaging camera. This method of flame hardening ensures that selected areas of the parts are hardened uniformly without any detrimental soft zones. 

This flame hardening process is used for a variety of applications.  Some are listed below.

Average Turnaround Time:  4 - 6 business days


  • Gears
  • Crane Wheels
  • Sheaves Wheels
  • Sprockets
  • Rollers
  • Rings


  • Max Diameter: 78"
  • Max Height: 24"
  • Max Weight: 20,000 lbs

Progressive Flame Hardening

For customers who require a more precise application of our expertise, Penna Flame offers progressive flame hardening. This technique involves rotating a part while a stationary flame head hardens the desired area. Temperatures are monitored by an infrared measuring system and rotation travels at a
pre-programmed speed.

Typical applications of this flame hardening technique include the applications below.

Average Turnaround Time:  4 - 6 business days.


  • Thrust Rings
  • Bearing Races
  • Gears
  • Sprockets


  • Max Diameter: 48"
  • Max Weight: 10,000 lbs
  • Ability to extend the diameter to 144" at a lesser weight capacity.

Progressive Spin Flame Hardening

“Uni-Max” is a roll flame hardening process developed by Penna Flame Industries. This hardening process begins with the review of all pertinent information necessary to choose the proper hardening parameters, and this can include material certifications.  Variables in some of the chemical elements can affect parameters such as case depth, surface hardness, and tempering temperature.  All parameters, including  preheat, austenizing (hardening) temperature, speed, and quench pressures are computer controlled and digitally monitored to ensure maximum surface hardness and case depth uniformity.  This is critical to providing you the highest-quality hardening process.

Average Turnaround Time:  5 - 8 business days
(Items with Deep Freeze Cryogenic and/or Stress Relieving requirements,
please add 4 - 6 business days.)



  • Rolls
  • Tubes
  • Cylinders
  • Piston Rods
  • Shafts


  • Max Length: 18' 1"
  • Max Dia: 36"
  • Max Weight: 20,000 lbs