The Metal Store’s free machining alloys provide all thebenefits of the latest developments in leadedor resulphurized alloy steels.Compared to similar non-leaded or non-resulphurized analyses, The Metal Store’simproved machining alloys machine as much as 50% faster and increase tool lifeas much as 300% with improved finish. In addition, all of these alloys developexcellent mechanical properties with heat treatment.

86L20 (Rycut 20)is a case hardening steel. A nickel, chrome, moly steel with excellent freemachining characteristics. Develops a uniformly hard case supported by a touch,ductile core and has relatively low distortion in heat treatment.Identification color: purple and green.

41L40 Annealed(Rycut 40) is a superior free machining direct hardening alloy. A chrome molyalloy with .40 carbon and .15/.35 lead addition can be quenched and tempered toa broad range of strength levels. Identification color: purple and yellow.

41L40/42/47 Quenched& Tempered (Rycut) is a medium carbon chrome-moly alloy with optimumstrength and hardness already in the bar. You save the cost and delay of heattreating, eliminate double handling for rough machining and finishing. Inaddition, the carbon content is matched to bar size giving uniform propertiesthroughout each section and from bar to bar across the broad size range.Surface hardness ranges between 269 and 321 Brinell. All bar stress relieved.Identification color: (thru 4”) purple with yellow dot, (over 4”) purple withpink dot.

41L50 Annealed(Rycut 50) has a higher carbon content to provide deeper hardenability foruniform through —hardening in larger sections with little loss inmachinability. Identification color: purple and pink.

4150 RSCT Annealed- The addition of sulphur along with a calcium treatment to this manganese,chrome, moly .50 carbon alloy provides improved machinability. Identificationcolor: purple and pink with black dot.

4150 RSCT Quenched& Tempered is a resulphurized and calcium treated machinable steelwhich has been quenched, tempered, machine-straightened and stress relieved todevelop ready-to-use strength and hardness. Surface hardness ranges between262/311 Brinell on all rounds as well as squares 3” and over. Identificationcolor: purple and black with pink dot. Flats and squares under 3” arenormalized, special straightened and stress relieved. (Brake Die Stock) Surfacehardness ranges between 241/302 Brinell. Identification color: purple and pinkwith white dot.


Calcium treated bars are fine-grained, calcium-aluminumtreated alloy steel with superior benefits for users of carbide tooling as wellas high-speed tooling. Speeds and feeds have been doubled and tool lifeincreased as much as 300%. Calcium treated bars deliver its machining benefitswithout sacrificing mechanical properties.

All standard ASI grades, except nitriding and boronanalyses, can be produced to a calcium treated practice and to appropriate ASTMspecifications. Any condition — hot rolled, cold drawn, annealed or heattreated - is available.

8620 CT is anas-rolled, case hardening, nickel-chrome moly steel. It develops a uniformlyhard case supported by a tough ductile core with very low distortion in heattreatment. Users of carbide and high speed tooling can greatly improveproductivity and increase tool life over AISI 8620. Identification color:orange, green and purple.

4140 CT ANNEALEDis one of the most commonly used medium carbon, direct oil hardening grades. Achrome-moly alloy, its superior machining characteristics offer users ofcarbide and high speed tooling cost savings over AISI 4150 annealed.Identification color: black, pink and purple.

4150 CT ANNEALED— A companion to 4140 annealed with increased carbon content yielding higherhardenability, yet offering superior machinability and tool life compared toAISI 4140 annealed. Identification color: yellow, black and purple.

4140 CT QTSR — Ageneral purpose “improved machining” alloy averaging .95% chromium and .20%molybdenum. Quenched, tempered and stress relieved to provide good hardnesspenetration, strength, toughness and ductility. Machining comparisons haveshown dramatic improvements overnon-calcium treated 4140 QTSR when carbide orhigh speed tools are used. Identification color: black and purple with yellowdot.

4150 CT QTSR — Amedium carbon, chrome-moly alloy, quenched, tempered and stress relieved toprovide good hardness penetration and minimum properties higher than 4140 QTSR.Identification color: black, pink and purple with yellow dot.


(For carbon manganese steels, 1117, see carbon barselection)

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

8620 — Mostwidely used of all case hardening alloys — truly general purpose, oil hardeningsteels with good core properties. Low in cost. Composition is balanced:normally .55% nickel, .50% chromium, .20% molybdenum. Minimum distortion andgrowth characteristics. Identification color: orange and green.


(For carbon manganese bars, 1141 &1144 , see carbon barsection)

The medium carbon and direct hardening steels in this groupoffer you the right combination of strength, toughness and hardness after oilquenching and tempering — plus machinability. When increased wear resistance isrequired in localized areas, they can be flame or induction hardened.Hardenability data is developed for each heat of steel and is furnished withThe Metal Store’s certification document.

4140/4150arewidely used medium carbon steels — truly general purpose alloys, low in cost.Nominal composition: .95% chromium and .20% molybdenum content. A broad rangeof strength and hardenability, strength, wear resistance, toughness andductility. Identification color: white and yellow.

4340 is a highlyalloyed steel, nominally 1.80% nickel, .80% chromium, .25% molybdenum —assuring deep hardness when oil quenched, with high strength characteristicsattained throughout the section. Used for heavily stressed parts operatingunder heavy-duty conditions. Identification color: white and yellow.

6150 is anelectric furnace alloy, nominally .95% chromium, .15% vanadium content. Hashigh surface hardness combined with low distortion characteristics and goodimpact resistance. Identification color: gold & pink.


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

4340 QTSR(Nikrome) has a high nickel/chromium content which gives outstanding depth ofhardness with high mechanical properties throughout the section — and has thestrength (302 BHN min.) and toughness to withstand severe service conditions.Identification color: white and orange with yellow dot.

4140/42 QT(Rycrome) 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 mechanicalproperties of ASTM-A193-B7, ASME SA193 (Latest) B7 and/or MIL-S-1222 (B7).Sizes over 7” conform to ASTM A434. Identification color: black with yellowdot. TG & P is black and red with yellow dot.

e.t.d. 150 ismade by the elevated temperature drawing process to obtain properties andstrengths usually achieved only by quenching and tempering. No heat treating isrequired — properties are in-the-bar as received. This steel machines fasterthan heat treated bars and compares favorably with cold drawn 4140 annealed.Identification color: black and gold with yellow dot.

4130 QT is ageneral purpose alloy. Low in cost, with a nominal .30% carbon, .95% chromiumand 20% molybdenum. Offers good strength and toughness for moderately stressedparts. Identification color: blue with pink dot.