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Small cylindrical metal armature with retaining ring 120V

Master Appliance

Master Appliance ARM-542 Armature Retaining Ring 120V

SKU CH-9QJT-NYRW4

Replacement armature with retaining ring for 120V hydraulic tools, compatible with HG-201A, HG-301A and HG-501A models

  • Product typeHydraulic Tool Accessories
  • Fits HG-201A and HG-301A heat-gun models
  • Compatible with HG-501A, HG-501A-D and HG-751A-C tools
  • Replaces armature on 1UNH8, 1UNH9 and 1YMJ7 part numbers
  • Works with 4Z714, 4Z715 and 5PYN3 replacement references
  • Supports 5PYN4, 5PYN6 and 5PYN8 service parts

Master Appliance ARM-542 Armature

The Master Appliance ARM-542 is a replacement armature with retaining ring rated for 120V operation. It serves as a direct service part for compatible Master Appliance heat guns and hydraulic tools requiring this specific component.

Compatibility limited to listed part numbers

This armature fits Grainger part numbers 1UNH8, 1UNH9, 1YMJ7, 4Z714, 4Z715, 5PYN3, 5PYN4, 5PYN6 and 5PYN8. It also matches manufacturer part numbers HG-201A, HG-301A, HG-501A, HG-501A-D and HG-751A-C. Tools outside this list will not accept the part.

New condition ensures reliable installation

Supplied new, the armature arrives free of wear or prior heat damage. The integrated retaining ring simplifies mounting by securing the assembly without separate hardware. Buyers needing a different voltage rating or a non-listed model number cannot use this component.

How it compares

Measured against everything we stock in Bits, Hole Saws & Accessory Kits, at today’s prices. Recalculated every night.

Price $25.99
Typical for this category: the median of 5,493 items is $27.99.

Specifications

Product
Brand nameMASTER APPLIANCE
Product typeHydraulic Tool Accessories

Questions about this item

Which compatible tool models work with the ARM-542 armature?

The ARM-542 fits HG-201A, HG-301A, HG-501A, HG-501A-D and HG-751A-C models, plus the listed Grainger part numbers.

What does the 120V rating mean for daily use?

It matches standard North American mains voltage, so the armature runs directly on shop power without a transformer.

How does the retaining ring affect installation on hydraulic tools?

The ring is pre-assembled on the armature, letting you drop the unit into compatible hydraulic accessories without separate ring fitting.

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