Acme Screw Material Specifications

Materials used in Helix acme nuts have been selected for low friction, minimum wear, long life, and clean operation.

Bronze Acme and Trapezoidal Nut

Special high tensile bronze is selected for our smooth running, anti-wedging bronze nuts.

  • Material: Helix Bronze
  • Tensile Yield: 50,000 psi
  • Tensile Ultimate: 65,000 psi
  • Hardness: HB75
  • Dynamic co-efficient of friction: 0.125 with Helix Lubricant

Nut specifications can be found in the Quick References on pages 18-19 and 60 of our Acme Screw Catalog. Flange and nut dimensions are listed with the appropriate screw data.

Plastic Acme and Trapezoidal Nut

The high strength and inherent lubricity of plastic Acme and Trapezoidal nut material can result in product life that can equal or exceed conventional nut materials.

Plastic Nut

  • Tensile Strength at 70°F: 8,000 psi
  • Compressive Strength at 70°F: 16,000 psi
  • PV Limit: 2,700 lubricated
  • Co-efficient of friction: 0.10 lubricated

PowerAc™ Flanges for Bronze and Plastic Nuts

Made from carbon steel with black oxided finish. See page 11 for Mounting and Pinning Acme Nut flange installation instructions.

SCREW TYPE MATERIAL THREAD CLASS LEAD ACCURACY SCREW DIA. SCREW LENGTHS
Rolled

Alloy

 Centralizing 2C or Stub ±.0003"/" up to 21⁄2" dia. 1⁄4" to 6" Limited only by material availability
  Stainless Centralizing 2C or Stub ±.0003"/" up to 11⁄2" dia. 1⁄4" to 11⁄2" Limited only by material availability
Milled Alloy Centralizing 2C or 3C ±.002"/ft 1⁄2" to 3" (single starts) up to 96"
  Stainless Centralizing 2C or 3C ±.002"/ft 1⁄2" to 3" (single starts) up to 96"
Ground Alloy Centralizing 3C or 4C ±.0005"/ft 1⁄4" to 4" up to 120"
  Stainless Centralizing 2C or 3C ±.0005"/ft 1⁄4" to 4" up to 120"

 

  ACME & TRAPEZODIAL STAINLESS STEEL
Screw Material 4140 300 Series
Minimum Hardness 200 Brinnel 170 Brinnel
Tensile Ultimate Strength 95,000 psi 85,000 psi
Finish Black Oxide Natural