IronRidge IR-HW-5164-01-M1 5/16 X 4 Sealing Washer Lag Screw

IronRidge 5/16" x 4" Stainless Steel Lag Screw with Sealing Washer (IR-HW-5164-01-M1)

The IronRidge Sealing Washer Lag Screw 5/16" x 4" (IR-HW-5164-01-M1) is a heavy-duty structural fastener designed for pitched roof mounting applications. Engineered to anchor solar racking attachments and flashing systems directly to underlying wood rafters, this 4-inch stainless steel lag screw delivers high pull-out capacity and shear strength to secure rooftop PV arrays against severe wind loads.

Frequently utilized alongside pitched roof mount flashing kits like the IronRidge QuickMount GF1 system, this hardware assembly features a bonded EPDM sealing washer. Upon torque application, the EPDM washer compresses under the hex head to form an immediate, watertight seal beneath the roof flashing, protecting rafter penetrations against weather intrusion and leaks.

• Type: Hex-head lag screw with bonded sealing washer (EPDM bonded to stainless)
• Diameter: 5/16″ threaded shaft
• Shaft Length: ~4″ (common length for this part in IronRidge roof mount kits).
• Material: Stainless steel (18-8 SS hardware used in IronRidge kits)
• Sealing Washer: EPDM bonded washer for water sealing under roof flashing/attachment
• Finish: Typically clear/shot-blasted stainless (no separate coating)