SLS® 14% Manganese Steel

Manganese Steel – SLS® 14% Manganese

SLS 14% Manganese Steel is one of the toughest steels available. Historically known as “Hadfield Manganese,” the chemical composition has not changed except for the addition of nickel and molybdenum to prevent embrittlement. Under cold work or impact, the alloy surface work hardens to three times its original state, making it the ideal material in high impact aplications.

This alloy is easily weldable and will retain its toughness at all times. All of these features, plus tensile strength in excess of 150,000 psi, make for ideal abrasion and impact resistant in high impact applications.


  • Maximum Impact Resistance
  • Long Service Life (As much as 10 times carbon steel)
  • Non-Magnetic Properties
  • Work Hardens to 550 — 650 BHN
  • St. Lawrence Custom Fabrication Available
  • Easy to Weld or Torch Cut
SLS 14% Manganese Steel

Available Stock Sizes

Thickness Width Lengths
1/4″ to 3″ 48″ to 96″ up to 288″
Rounds Squares Flats
1/2″ 2″ 1″ 3/8″ x 2″
5/8″ 2¹/₂″ 1¹/₂″ 1/2″ x 2″, 3″, 4″, 6″
3/4″ 3″ 2″ 3/4″ x 2″, 3″, 4″,6″
7/8″ 3¹/₂″ 2¹/₂″ 1″ x 2″, 3″, 4″,6″,8″
1″ 4″   2″ x 4″, 5″
1¹/₈″ 4¹/₂″    
1¹/₄″ 5″    
1¹/₂″ 5¹/₂″    
1³/₄″ 6″    

*All round bars 3¹/₂″ dia. and over are oversized (+¹/₈″ to + ³/₁₆″). Standard lengths are 20 ft.

Chemistry (typical %)

C Mn Si Cr Mo Ni
1.00-1.25 11.50-14.00 .15 -.30 .50* .25* .40*

*max %

Steel Plate Comparison

Product Abrasion Resistance Impact Resistance Weldability Machinability Forming Cutting
MAN-CRO 450F G - VG G G M - F F - G G - VG
Ultra-Met Standard E G E(1) M(2) F G(4)
Ultra-Met Impact VG G - VG E(1) M(2) M - F G(4)
Ultra-Met Abrasion E - S G E(1) M(2) F G(4)
Hardlite E G E(1) M(2) F G(4)
SLS 14% Manganese F E VG(3) M G G

S: Superior, E: Excellent, VG: Very Good, G: Good, F: Fair, M: Marginal

(1) Carbon Base Only

(2) EDM, Plasma or Air Arc holes only

(3) When welding Manganese to any other metal, use 309 or 310 SS electrode w/ minimum heat input

(4) Plasma, waterjet or laser

Mechanical Properties (typical)†

Yield PSI Tensile PSI Elong 2″ % Reduction of Area % Hardness BHN † †
120K- 135K 140K- 170K 11%- 19% 20-24 550-650

Thermal coefficient of expansion 10.2 x 10-⁶/⁰ F/100°- 300°F range. Magnetic permeability 1.02. (Modulus of elasticity 24-30,000,000 psi.)

† Endurance limit (polished specimen) 39,000 psi. Electrical resistivity 66 microhm/cm – 32°F. Thermal Conductivity 93.6 BTU/sq. ft./hr./°F/in. at 70° F.

† † In work hardened state.


We recommend the use of St. Lawrence's fabrication services to eliminate processing and fabrication errors.


Austenitic Manganese Steels should be cut without pre or post-heating. Use of iron powder or plasma-arc cutting, when cutting material over 1/2″ thick, may help to prevent ragged edges. Use of oxy-acetylene is not recommended.


SLS 14% Manganese can be cold formed in brake or rolled in thicknesses up to and including 1/2″. A strength ratio of 2:1 on bending or rolling equipment is required compared to mild steel. More generous radii are suggested on most cold forming applications. SLS 14% Manganese Steel is fully treated for extensive fabrication – this insures against cracks or seams following forming and machining.


SLS 14% Manganese Steel is not a free machining steel. Metal will tend to work harden just ahead of the cutting tool. Various techniques have been developed to drill or machine this type of material. Generally, the following technique or procedure has been most successful:

1) Use blunt drills – Tungsten Carbide (or) High Speed.

2) Sulphurized cutting oil.

3) Heavy Feed (once drilling or machining has started, complete operation without let-up.)


CAUTION: Oxy-acetylene gas welding is not recommended.

1) General Instructions

SLS 14% Manganese Steel lends itself to higher d uctility in the weld heataffected zone since all stock is thermally treated before shipment. Control of welding heat input is essential to minimize embrittlement. None of these steels should be given a low temperature (1000° F/1200° F) stress-relief after welding, due to the possibility of embrittlement.

2) Preheating

Authentic Manganese Steels should not be pre-heated nor post-heated for welding.

3) Consumables

For manual metal-arc welding, several good proprietary high-manganese (AWS E-FEMN-A) electrodes are available. Best quality welds are made with austentic stainless (AWS-E309 or 310) electrodes, although such joints may not be as abrasion-resistant as those made with high-manganese electrodes.