Brass: The Cost-Effective Choice Superior Machinability (steel scrap has little value) creating an advantageous net material cost for customers while improving control over Performance and cost are critical factors when selecting raw materials costs. materials for screw machine products. The superior machinability of brass offers higher productivity and lower And while brass easily meets the yield strength per-part cost compared to other materials. requirements for small component parts, its superior machinability means higher productivity and lower per- part cost. When you’re buying screw machine parts, The Standard by Which Others are Judged you’re really paying for machine time. The faster the cut, While all brasses are intrinsically easy to machine,Brass: the The Cost-Effectivethe lower Choice the cost. What’s more, brass naturally resists additionPerformance of smalland cost amounts are critical of lead factors to brasseswhen selecting further materials for screwcorrosion, machine eliminating products. The the superior need for machinability costly protective of brass offers improveshigher productivity this property and lower and theper- well-knownpart cost compared “free cuttingto other materials.electroplating or coatings which can add more than 20 brass” (UNS Alloy C36000) is universally accepted as cents per pound of product. settingMachinability the standard The Standard by which by all Which other Others materials are Judged are judged when machinability is being assessed. Higher The numbers say it all. In terms of finished part cost, the machiningWhile all brasses speeds are and intrinsically lower rates easy ofto toolmachine, wear the mean addition that of small amountsexample of below lead to demonstrates brasses further that improves free-cutting this property brass and is the overallwell-known production "free cutting costs brass" are minimized, (UNS Alloy C36000)tolerances is universally are held accepted>37% as setting less expensivethe standard than by which 12L14 all leadedother materials steel. are duringjudged whenlong productionmachinability runs is being and assessed.surface finish Higher ismachining excellent. speeds and lower rates of tool wear mean that overall production costs Forare minimized,comparison, tolerances C36000 are brass held is during about long five production times more runs and surface finish is excellent. For comparison, C36000 brass is about five times more machinable than leaded steel. machinable than leaded steel. Finished Part Cost Comparison UniversalUniversal Machinability Machinability RatingsRatings (ASTM E618) E618) Production Data* 100 Brass Steel 80 (UNS 36000) (AISI 12L14) 60 Part Weight 0.013 lbs 0.01196 lbs 40 Turnings Ratio** 63% 63% Cycle Time 3.65 sec/part 7.66 sec/part 20 Efficiency Factor† 0.80 0.70 0 Material Cost1 $3.19/lb $0.76/lb Brass (C36000) Aluminum (2011-T3) Steel (12L14) Turnings Value1 $2.53/lb $0.12/lb Total Cost/1,000 Parts1 $138.47 $219.68 Cost Effectiveness First Cost vs. Finished Cost * Data on inserts for molded plastic obtained from Midwestern machine shop in 2014 First Cost vs. Finished Cost ** Percentage of raw material used to make parts The off-the-shelf price of brass may sometimes be higher than alternative† Accountsmaterials, for tool but changes, the rawrestocking material time, maintenance cost is only part of the overall Thecost off-the-shelfpicture. Brass turnings price of can brass be reclaimedmay sometimes for 75- 85%be higherof the original 1.brass Costs valueof both brass(steel and scrap steel fluctuate has little with value)market conditions, creatin gbut an the assumptions made advantageous net material cost for customers while improving control overhere raware consistent materials with pricescosts. that have existed in recent years. There is no intent to imply than alternative materials, but the raw material cost is that the prices assumed here are current; however, they reasonably represent the metals’ only part of the overall cost picture. Brass turnings can relative market prices. And while brass easily meets the yield strength requirements for small component parts, its superior machinability means higher be reclaimed for 75-85% of the original brass value productivity and lower per-part cost. When you're buying screw machine parts you're really paying for machine time. The faster the cut, the lower the cost. What's more, brass naturally resists corrosion, eliminating the need for costly protective electroplating or coatings which can add more than 20 cents per pound of product. www.copper.org The numbers say it all. In terms of finished part cost, the example below demonstrates that free-cutting brass is >37% less expensive than 12L14 leaded steel. Finished Part Cost Comparison Inserts for Molded Plastic Production Data* Brass (UNS 36000) Steel (AISI 12L14) 1. Costs of both brass and steel fluctuate with market conditions, but the assumptions made here are consistent with prices that have existed in recent years. There is no intent to imply that the prices assumed here are current; however, they reasonably represent the metals' relative market prices. Brass: The Cost-Effective Choice Total Weight of Raw Materials 13 1 35.14 turnings ratio Brass: 1,000 x (1−0.63) = 1,000 11.96 1 32.32 turnings ratio Steel: 1,000 x (1−0.63) = 1,000 Raw Material Cost 35.14 $3.19 $112.10 Brass: 1,000 x = 1,000 32.32 $0.76 $24.56 Steel: 1,000 x = 1,000 Net Material Cost ( ) $112.10 $2.53 22.14 $56.09 turnings value turnings weight Brass: 1,000 1,000 1,000 –( x ) = $24.56 $0.12 20.50 $22.10 turnings value turnings weight Steel: 1,000 – x 1,000 = 1,000 Machine Shop Labor Cost 3,650 1 ℎ 1 $65 $82.38 efficiency factor labor Brass: 1,000 x 3,600 x 0.80 x ℎ = 1,000 7,660 1 ℎ 1 $65 $197.58 efficiency factor labor Steel: 1,000 x 3,600 x 0.70 x ℎ = 1,000 Total Cost per 1,000 Parts $56.09 $82.38 $138.47 Net Material Cost Labor Cost Brass: 1,000 + 1,000 = 1,000 $22.10 $197.58 $219.68 Net Material Cost Labor Cost Steel: 1,000 + 1,000 = 1,000 Fabricating this part from brass is 37% cheaper than steel! www.copper.org A7033 XX/15.