3.6.3 HVAC SCREWS
3.6.3.1 PRODUCT DESCRIPTION
For decades , the conventional screws utilized for HVAC duct fabrication and installation have gone unchanged . Many contractors prefer sharp point screws for their off angle fastening but the screws are limited to lighter gauge steel . Selfdrilling screws cover heavier gauge steel but are prone to “ walking .” This can lead to lost productivity , especially when working in spaces with limited access .
Hilti has blended the best of both fasteners with the new S-MS HVAC zip screws . Although they function like and
3.6.3.2 MATERIAL SPECIFICATIONS
have the advantages of self-piercing screws , the sharp HVAC zip screws are engineered to handle heavier gauge steel , fastening sheet steel from 16 to 28 gauge with their innovative HyperThread technology . HVAC zip screws can draw the steel sheets together , pierce cleanly with almost no metal filings and feature high profile heads for secure driving .
Hilti also supplies high quality sharp point and self-drilling screws for HVAC applications .
3.6.3.1 Product description 3.6.3.2 Material specifications 3.6.3.3 Technical data 3.6.3.4 Installation instructions 3.6.3.5 Ordering information
S-MS HWH HVAC Zip Screws (# 8 and # 10 )
Fastener Fastener Material Fastener Plating 4
S-MS HWH HVAC Zip Screws (# 8 Screw ) Carbon Steel 3 to 8 µ m Zinc S-MS HWH HVAC Zip Screws (# 10 Screw ) Carbon Steel 5 µ m Zinc 1 HWH Sharp HVAC Screws (# 8 and # 10 ) Carbon Steel Zinc 3
HWH Self-Drilling HVAC Screws (# 8 , # 10 and # 12 ) Carbon Steel 5 µ m Zinc 2
1 EN / ISO 4042 A / 3 / E . 2 EN / ISO 4042 A3F . 3 Minimum 24 hours no red rust when tested in accordance with ASTM B117 . 4 Reference Section 2.3.3.1 for more information on platings .
3.6.3.3 TECHNICAL DATA
Ultimate tensile strengths - pullout ( tension ), lb ( kN ) 1 , 2 , 4 , 5 , 6
Screw designation
S-MS 8-18x1 / 2 HWH
S-MS 10-12x3 / 4 HWH –
# 8 HWH Sharp
# 10 HWH Sharp
Thickness of member not in contact with the screw head , ga ( in .) 28 26 24 22 20 18 16 ( 0.015 ) ( 0.018 ) ( 0.024 ) ( 0.030 ) ( 0.036 ) ( 0.048 ) ( 0.060 )
110 150 200 260 330
( 0.49 ) ( 0.67 ) ( 0.89 ) ( 1.16 ) ( 1.47 ) 160 230 305 350 450 ( 0.71 ) ( 1.02 ) ( 1.36 ) ( 1.56 ) ( 2.49 ) 110 150 200 260 ( 0.49 ) ( 0.67 ) ( 0.89 ) ( 1.16 ) 130 160 230 305 350 ( 0.58 ) ( 0.71 ) ( 1.02 ) ( 1.36 ) ( 1.56 )
S-MD 8-18 HWH 3 – – –
S-MD 10-16 HWH 3 , 7 – – – –
S-MD 12-14 HWH 3 , 7 – – – –
– –
–
– – –
– –
190 225 300 375
( 0.85 ) ( 1.00 ) ( 1.33 ) ( 1.67 ) 260 350 435 ( 1.16 ) ( 1.56 ) ( 1.93 ) 295 395 495 ( 1.31 ) ( 1.76 ) ( 2.20 )
1 The lower of the ultimate pullout , pullover , and tension fastener strength of screw should be used for determination of allowable or factored resistance loads per footnote 4 . 2 Unless otherwise noted , load values based upon testing completed in accordance with AISI S905 . 3 Load values based upon calculations done in accordance with Section J4 of AISI S100 . ANSI / ASME standard screw diameters were used in the calculations and are listed in the tables . 4 AISI S100 recommends a safety factor of 3.0 be applied for allowable strength design ( ASD ), a ф factor of 0.5 be applied for LRFD design or a Φ factor of 0.4 be applied for LSD design . 5 The load data in the table is based upon sheet steel with F u
= 45 ksi . For F u = 55 ksi steel , multiply values by 1.22 . For F u
≥ 65 ksi steel , multiply values by 1.44 . 6 Refer to Section 3.6.3.5 to ensure optimal drilling capacities . 7 Load data for thicker steel connections available . Please reference Section 3.6.2 .
HWH HVAC Sharp Point Screws (# 8 and # 10 )
S-MD HWH HVAC (# 8 , # 10 and # 12 )
Approvals / Listings
ICC-ES ( International Code Council ) ESR-2196 with LABC / LARC Supplement ( S-MD HWH Self-Drilling Screws )
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