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Johns Manville Extra High Load #21 Phillips Membrane Fasteners, 6 in. or 8 in.
Regular price $526.00Johns Manville Extra High Load #21 Phillips Membrane Fasteners, 6 in. or 8 in.
Johns Manville Extra High Load fasteners are case-hardened steel, corrosion-resistant coated #21 screws with a #3 Phillips head and drill point, made to mechanically attach thermoplastic membranes. Choose 6 in. (500/box) or 8 in. (250/box). Pair them with the 3 in. galvalume-coated Extra High Load Plate with eye hooks.
Key Features:
- High pullout capacity: Extra High Load #21 wire size fasteners are designed for high-load mechanical attachment of thermoplastic membranes.
- Drill point tip: Each screw has a drill point for fast penetration into steel decks.
- Phillips drive: #3 Phillips head accepts standard roofing screw guns.
- Corrosion-resistant coating: Fasteners are coated for corrosion resistance; black fasteners with gray plates.
- Matching 3 in. plate: The Extra High Load Plate is 3 in. round galvalume-coated steel with eye hooks and an oversized hole for the larger wire size.
- Two lengths: Available in 6 in. boxes of 500 and 8 in. boxes of 250 to match deck and insulation thickness.
Specifications Table:
| Specification | Details |
|---|---|
| Brand | Johns Manville |
| Sell unit | 1 box (500 for 6 in., 250 for 8 in.) |
| Product line | JM Extra High Load membrane fasteners |
| Available sizes | 6 in. #21 (500/box); 8 in. #21 (250/box) |
| Gauge | #21 wire size |
| Material | Fastener: case-hardened steel; Plate: galvalume-coated steel |
| Head | #3 Phillips head with drill point |
| Plate size | 3 in. (7.6 cm) round with eye hooks |
| Color / finish | Black fasteners, gray plates; corrosion-resistant coating |
| Pack quantity | 500 per box (6 in.) or 250 per box (8 in.) |
| Intended use | Mechanical attachment of thermoplastic membranes to steel decks |
Coverage & How Much You Need:
A box of 6 in. fasteners (500) or 8 in. fasteners (250) covers field rows at your specified fastener density; divide the required fastener count by the box quantity to size ordering. Plates are ordered separately to match.
Fit and Compatibility:
Designed for mechanical attachment of thermoplastic membranes with the matching JM Extra High Load 3 in. plate, which has an oversized hole to accept the larger #21 wire size. Plates are sold separately; verify deck thickness before choosing 6 in. versus 8 in. length.
Frequently Asked Questions (FAQ):
Q: What sizes are available?
A: Two variants: 6 in. #21 fasteners, 500 per box, and 8 in. #21 fasteners, 250 per box.
Q: What is included?
A: One box of fasteners only; the 3 in. Extra High Load Plate is sold separately.
Q: What membranes do they attach?
A: They are used to mechanically attach thermoplastic membranes such as TPO.
Q: What driver do I need?
A: The screws use a #3 Phillips head; use a compatible screw gun with depth-setting clutch.
Q: What plate do I pair with them?
A: The JM Extra High Load Plate, a 3 in. galvalume-coated steel round with eye hooks and an oversized hole for the #21 wire.
Q: Are they corrosion resistant?
A: Yes, the fasteners carry a corrosion-resistant coating, and the plates are galvalume-coated steel.
Expert Verdict — Reviewed by the SuperArbor Pro Desk
Choose the 6 in. screw for thinner insulation stacks and the 8 in. screw where thicker assemblies require deeper embedment into steel deck. Because the #21 wire is larger than standard fasteners, always pair with the Extra High Load Plate so the hole accommodates the wire, and run installation torque tests to set clutch depth before production fastening.
Wear eye protection when fastening and verify fastener penetration through the deck from below before full installation.
Order JM Extra High Load #21 Phillips fasteners in 6 in. or 8 in. boxes for high-load membrane attachment.
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