High Strength Steels

Mirraloy® FM Pre-Keyed

Free Machining, Turned Ground & Polished,  Full Length Keyed 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 Rockwell “C” 26. This shafting material is based on a modified 1144 steel.

Provides superior strength and toughness in service due to its micro alloyed chemistry. The following tests: roto bar, mechanical, warpage, and machinability are performed at the manufacturing level, prior to keying the shaft, to ensure proper product performance in the field. Call or email us for a quote.

Exhibits nearly 50% more tensile strength than that of a C1018 and up to 25% more than C1045.


Key Features

Clean Steel Technology – a manufacturing process that delivers consistent steel through control and refinement of the melt.

Proprietary Chemistry – a chemistry that offers excellent cleanliness and a well defined grain structure to provide fatigue resistance when material is in service.

Machine Straightened – eliminates excessive bow and distortion. Our standard straightness is 1/8″ in any 5 feet, better than twice the industry standard.

Precision Finish – “near” bearing-fit shaft with a precision finish of approximately RMS 15.

Strength Comparison Chart* (Based on 1/2″ Dia. Specimen)

Mirraloy FMC1045C1018
Tensile Strength133,000 PSI91,000 PSI70,000 PSI
Yield Strength110,000 PSI77,000 PSI50,000 PSI

Typical Mechanical Properties (Based on 1/2″ Dia. Specimen)

Hardness, Brinell (Rockwell)260 BHN (Rc “26”)
Tensile Strength (Typ.)133,000 P.S.I.
Yield Strength (Typ.) 110,000 P.S.I.
Elongation in 2″8% min.
Reduction of Area25% min.
Machinability Rating83% of carbon steel

Available Lengths

10/12 Foot Random Lengths, 20/24 Ft Random Lengths, and Custom Cut-To-Lengths

*Available Sizes

Keyed Rounds
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

*Small diameter shafts may have modified analysis and/or variations in thermal treatment.

Typical Diameter Tolerances

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

Boxing is recommended to protect during shipment.

Sheffield™ FM Redi-Keyed is the past protected tradename of North American Steel Company.

Centra-Key is the past protected tradename of Ludlow Steel Company.

Request a Quote

  • This field is for validation purposes and should be left unchanged.

For our bar fabrication capabilities and services, click on the button below.