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Free machining alloys provide all the benefits of the latest developments in leaded or resulphurized alloy steels. Compared to similar non-leaded or non-resulphurized analyses. The improved machining alloys machine as much as 50% faster and increase tool life as much as 300%, with improved finish. In addition, all of these alloys develop excellent mechanical properties with heat treatment.

86L20 is a case hardening steel. A nickel, chrome, moly steel with excellent free machining characteristics. Develops a uniformly hard case supported by a tough, ductile core and has relatively low distortion in heat treatment.

41L40 Annealed is a superior free machining direct hardening alloy. A chrome moly alloy with .40 carbon and .15/.35 lead addition can be quenched and tempered to a broad range of strength levels.

41L40/42/47 Quenched & Tempered is a medium carbon chrome-moly alloy with optimum strength and hardness already in the bar. You save the cost and delay of heat treating. In addition, the carbon content is matched to bar size giving uniform properties throughout each section and from bar to bar across the broad size range. Surface hardness ranges between 269 and 321 Brinell. All bars stress relieved.

41L50 Annealed has a higher carbon content to provide deeper hardenability for uniform through-hardening in larger sections with little loss in machinability.

4150 RSCT Annealed. The addition of sulphur along with a calcium treatment to this manganese, chrome, moly .50 carbon alloy provides improved machinability.

4150 RSCT Quenched & Tempered is a resulphurized and calcium treated machinable steel which has been quenched, tempered, machine-straightened and stress relieved to develop ready-to-use strength and hardness. Surface hardness ranges between 262/311 Brinell on all rounds as well as squares 3 and over. Flats and squares under 3 are normalized, special straightened and stress relieved.(Brake Die Stock) Surface hardness ranges
between 241/302 Brinell.


The ability to develop a hard case supported by a tough, ductile core is characteristic of case hardening alloys with the exact properties developed, depending on the type of alloy selected and the manner of heat treatment.

8620 Most widely used of all case hardening alloys truly general purpose, oil hardening steels with good core properties. Low in cost. Composition is balanced: nominally .55% nickel, .50% chromium, .20% molybdenum. Minimum distortion and growth characteristics.


The medium carbon and direct hardening steels in this group offer you the right combination of strength, toughness and hardness after oil quenching and tempering plus machinability. When increased wear resistance is required in localized areas, they can be flame or induction hardened.

4140/4150 are widely used medium carbon steels truly general purpose alloys, low in cost. Nominal composition: .95% chromium and .20% molybdenum content. A broad range of strength and toughness is attainable through variations in heat treatment. Good hardenability, strength, wear resistance, toughness and ductility.

4340 is a highly alloyed steel, nominally 1.80% nickel, .80% chromium, .25% molybdenum assuring deep hardness when oil quenched, with high strength characteristics attained throughout the section. Used for heavily stressed parts operating under heavy-duty conditions.

6150 is an electric furnace alloy, nominally .95% chromium, .15% vanadium content. Has high surface hardness combined with low distortion characteristics and good impact resistance.


These alloys have been quenched and tempered (except e.t.d. 150s rounds which are elevated temperature drawn and 4150 Mod. RS flats and squares under 3 which are normalized and stress relieved) so that strength and hardness is already developed, ready for use. Many hot rolled bars are machine straightened and can be furnished with or without stress relieving. All cold drawn bars are fully stress relieved after drawing so that distortion during machining
is held to a minimum.

4340 QTSR (Nikrome) has a high nickel/chromium content which gives outstanding depth of hardness with high mechanical properties throughout the section and has the strength (302 BHN min.) and toughness to withstand severe service conditions.

4140/42 QT is a general purpose alloy, low in cost, nominally .95% chromium and .20% molybdenum. Has good hardness penetration, strength, toughness, and ductility. Sizes thru 7'comply with the chemical and mechanical properties of ASTM-A193-B7, ASME SA193 (Latest) B7 and/or MIL-S-1222 (B7). Sizes over 7 conform to ASTM A434.

e.t.d. 150 is made by the elevated temperature drawing process to obtain properties and strengths usually achieved only by quenching and tempering. No heat treating is required properties are in-the-bar as received. This steel machines faster than heat treated bars and compares favorably with cold drawn 4140 annealed.

4130 QT is a general purpose alloy. Low in cost, with a nominal .30% carbon, .95% chromium and 20% molybdenum. Offers good strength and toughness for moderately stressed parts.

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