BLAZER Self-Drilling Screws with Sealing Washers

BLAZER self-drilling screws with sealing washers drill and tap through metal in one pass. They fasten panels over insulation to the steel structure beneath, which suits metal roof replacement with exposed-fastener panels. Each screw has a hex washer head and a drill point from DP1 to DP5.

Two washer styles are made. The BOND-SEAL washer is EPDM vulcanized to a 20 gauge galvanized backing. It is 20 ga G-90 galvanized steel with a .062 in thick non-conductive EPDM layer and a 15 mm OD. The FLANGE-SEAL head has a deep undercut that entraps a .125 in thick non-conductive EPDM washer. Both styles carry the TRI-SEAL long life coating for corrosion protection. Special washer sizes are available on request.

• #12-14 DP2: 3/4 to 3 in long
• 1/4-14 DP1: 7/8 in long (VRT point); drills and taps 0.024 to 0.072 in of steel
• 1/4-14 DP3: 3/4 to 10 in long; drills and taps 0.035 to 0.250 in of steel
• 5/16-12 DP3: 1 to 8 in long; drills and taps 0.048 to 0.175 in of steel
• #12-24 DP5: 1-1/4 to 2 in long; drills and taps 0.175 to 0.500 in of steel
• 1/4-20 DP5: 1-1/2 to 8 in long, with a 5/8 in OD washer face; drills and taps 0.175 to 0.500 in of steel
• #12-14 DP3 (FLANGE-SEAL head): 1 to 4 in long; drills and taps 0.024 to 0.210 in of steel
• 1/4-14 DP1 (FLANGE-SEAL head): 7/8 in long (VRT point)
• 1/4-14 DP3 (FLANGE-SEAL head): 1 to 2 in long

1. Determine the screw drill point type. Add up the total thickness that will be drilled by the screw. Select the drill point (DP) type and screw size from the drilling and tapping thickness chart.
2. Determine the screw length. Measure from the top surface of the material being fastened to the underside of the metal that will be drilled and tapped, allowing for any void or insulation. This is the attachment thickness. Select a screw length where the attachment thickness is less than or equal to the load bearing length.

At least three full threads extend beyond the material being fastened. The load bearing length is the maximum attachment thickness for each length.

• Head: hex washer head (HWH).
• BOND-SEAL head sizes: #12 diameter, 5/16 in HWH; 1/4 in diameter, 3/8 in HWH; some 1/4 in diameter items, 5/16 in and 3/8 in HWH; 5/16 in diameter, 3/8 in HWH.
• FLANGE-SEAL head: 5/16 in HWH with flange undercut.
• Washer: EPDM, non-conductive. BOND-SEAL is vulcanized to a 20 ga G-90 galvanized steel backing, 15 mm OD.
• Coating: TRI-SEAL long life coating.
• Seating: tighten until a slight circle of sealant extrudes to the outer edge of the backing. The backing turns up when too tight, and the sealant is not compressed when too loose.