High Strength Steels

Kromite® #3

4140/4150 (modified) Hot Roll, Heat Treated, High Strength Alloy

Kromite #3 is a modified 4140/4150 steel. Typical hardness is Rockwell “C” 28/34. This chromium and molybdenum based alloy is electric furnace melt, vacuum degassed, stress relieved, and machine straightened. It is offered in the hot roll, heat treated condition. Typical tensile strength is 156,000 PSI. This proprietary product provides elevated strength, deep uniform hardness, excellent cleanliness, and refinement to the grain structure which enhances the fatigue resistance and overall performance of the steel. Call or email us for a quote.

Kromite #3 is a good choice of alloy steel for machined parts requiring higher resistance to toughness, flex, torque and general wear.

Consideration should be given to use Kromite #3 in place of certain commercial alloy and carbon steel grades including: AISI 4130, 4140, 4150, 4340, 1018, 1020 and 1045 depending upon the requirement.

Key Features

Clean Steel Technology – a manufacturing process that delivers consistent steel through control and refinement of the melt.

Proprietary Chemistry – a chemistry that offers excellent cleanliness and a well defined grain structure to provide fatigue resistance when material is in service.

Electric Furnace Melt – offers greater quality control at the mill including refinement of chemistry, grain size and shape.

Vacuum Degassed – eliminates many impurities found in standard commercial grade alloys. The result is a better, cleaner, and stronger product that extends service.

Heat Treated – eliminates excessive cost in heat treatment. Our material is thermally treated (as delivered) to a hardness of 269/341 BHN.

Machine Straightened – eliminates excessive bow and distortion. Our standard straightness is 1/8″ in any 5 feet, better than twice the industry standard (for rounds and squares only).

Stress Relieved – reduces the likelihood of material “walking” or moving during machining.

Typical Mechanical Properties (Based on 1/2″ Dia. Specimen)

Hardness, Brinell (Rockwell)269/341 BHN (Rc “28/34”)
Tensile Strength156,000 P.S.I.
Yield Strength123,500 P.S.I.
Grain Size95% – 8
Elongation in 2″ 17%
Reduction of Area55%
Machinability Rating%50

Available Lengths

10/12 Foot Random Lengths, 20/24 Foot Random Lengths, Custom Cut-To-Lengths

Available Sizes

Rounds
1/2″
5/8″
3/4″
7/8″
1″
1-1/8″
1-1/4″
1-3/8″
1-1/2″
1-5/8″
1-3/4″
1-7/8″
2″
2-1/8″
2-1/4″
2-3/8″
2-1/2″
2-5/8″
2-3/4″
2-7/8″
3″
3-1/4″
3-1/2″
3-3/4″
4″
4-1/4″
4-1/2″
4-3/4″
5″
5-1/4″
5-1/2″
5-3/4″
6″
6-1/4″
6-1/2″
6-3/4″
7″
7-1/4″
7-1/2″
7-3/4″
8″
8-1/4″
8/1/2″
8-3/4″
9″
9-1/2″
9-3/4″
10″
10-1/2″
11″
11-1/4″
11-1/2″
12″
13″
13-1/2″
14″
15″
16″
Squares
1/2″
5/8″
3/4″
7/8″
1″
1-1/8″
1-1/4″
1-1/2″
1-3/4″
2”
2-1/2″
3”
3-1/2″
4”
6”
Flats
1-4″ x 1″
1/4″ x 1-1/2″
1/4″ x 2″
1/4″ x 3″
1/4″ x 4″
1/4″ x 5″
1/4″ x 6″
3/8″ x 1-1/2″
3/8″ x 2″
3/8″ x 2-1/2″
3/8″ x 3″
3/8″ x 4″
1/2″ x 1″
1/2″ x 1-1/2″
1/2″ x 2″
1/2″ x 2-1/2″
1/2″ x 3″
1-2″ x 3-1/2″
1/2″ x 4″
1/2″ x 5″
1/2″ x 6″
5/8″ x 2″
5/8″ x 3″
3/4″ x 1-1/2″
3/4″ x 2″
3/4″ x 2-1/2″
3/4″ x 3″
3/4″ x 4″
3/4″ x 5″
3/4″ x 6″
1″ x 1-1/4″
1″ x 1-1/2″
1″ x 2″
1″ x 2-1/2″
1″ x 3″
1″ x 4″
1″ x 5″
1″ x 6″
1-1/4″ x 2″
1-1/4″ x 2-1/2″
1-1/4″ x 3″
1-1/4″ x 3-1/2″
1-1/4″ x 4″
1-1/2″ x 2″
1-1/2″ x 2-1/2″
1-1/2″ x 3″
1-1/2″ x 4″
1-1/2″ x 5″
1-1/2″ x 6″
2″ x 2-1/2″
2″ x 3″
2″ x 3-1/2″
2″ x 4″
2″ x 5″
2″ x 6″
2-1/2″ x 3-1/2″
2-1/2″ x 4″
2-1/2″ x 6″
3″ x 4″
3″ x 5″
3″ x 6″

Hot Roll Annealed Bar Stock, Brake Die Stock and Custom Forgings are all available upon request. Typically, 10″ Rounds and above are furnished as Rough Turned Oversized, to finish to the nominal size, and have an approximate 500 RMS. All squares over 4-1/2″ are produced from plate; standard plate tolerances apply. Certain flats may be furnished from cut plate; standard plate tolerances apply.

Applications

  • Arbors
  • Bolts
  • Crank Shafts
  • Drive Shafts
  • Drag Line Parts
  • Feed Screws
  • Gears
  • Hubs
  • Journals
  • Line Shafts
  • Mandrels
  • Pinions
  • Stub Shafts
  • Tie Rods
  • Worm Gears

Sheffield™ #10 is the past protected Trade Name of North American Steel Company.

Centrex® HR is the past protected Trade Name of Ludlow Steel Company.

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