High Strength Steels

Mirraloy® FM Pre-Keyed

Free Machining, Keyed TGP Shaft

Mirraloy FM Pre-Keyed is designed to provide a high degree of accuracy while also exhibiting high strength, ease of machining, and long-term wear life. Most other keyed shafts are typically “Cold Roll” which generally means you get mild steel. Typical hardness is 260 BHN. This shafting material is based on a modified 1144 steel.

Mirraloy FM Pre-Keyed provides superior strength and toughness in service due to its micro alloyed chemistry. Roto bar, mechanical, warpage, and machinability tests are performed at the manufacturing level, prior to keying the shaft, to ensure proper products performance in the field.  Call or email us for a quote.

Exhibits nearly 50% more tensile strength than that of a 1018 and up to 25% more than 1045.



Pre-Keyed Full Length

Free Machining

Precision TGP Finish

Machine Straightened

Fatigue Resistant

Clean Steel Technology 

Typical Properties*

Hardness260 BHN
Tensile 133,000 P.S.I.
Yield 110,000 P.S.I.
Elongation in 2″8% min.
Machinability 83% of 1212

*Based on 1/2″ test piece


Available Sizes

1/2″ Dia. with 1/8″ x 1/16″ Keyway
5/8″ Dia. with 3/16″ x 3/32″ Keyway
3/4″ Dia. with 3/16″ x 3/32″ Keyway
7/8″ Dia. with 3/16″ x 3/32″ Keyway
1″ Dia. with 1/4″ x 1/8″ Keyway
1-1/8″ Dia. with 1/4″ x 1/8″ Keyway
1-3/16″ Dia. with 1/4″ x 1/8″ Keyway
1-1/4″ Dia. with 1/4″ x 1/8″ Keyway
1-3/8″ Dia. with 5/16″ x 5/32″ Keyway
1-7/16″ Dia. with 3/8″ x 3/16″ Keyway
1-1/2″ Dia. with 3/8″ x 3/16″ Keyway
1-5/8″ Dia. with 3/8″ x 3/16″ Keyway
1-15/16″ Dia. with 1/2″ x 1/4″ Keyway
2″ Dia. with 1/2″ x 1/4″ Keyway
2-3/16″ Dia. with 1/2″ x 1/4″ Keyway
2-7/16″ Dia. with 5/8″ x 5/16″ Keyway
2-15/16″ Dia. with 3/4″ x 3/8″ Keyway



10/12 Ft. R/L and Custom Cuts

Typical Diameter Tolerances

1/2” to 1-1/2” Round
Over 1-1/2” to 2-15/16” Round

Comparison of Mirraloy® FM vs Commercial Grade Carbon Steels*

Mirraloy® FM10451018
Tensile Strength133,000 PSI91,000 PSI70,000 PSI
Yield Strength110,000 PSI77,000 PSI50,000 PSI

*Based on 1/2″ test piece

Boxing is recommended to protect during shipment.

(Equivalent to Sheffield™ FM Redi-Key)

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