General Design Principles for DuPont Engineering Polymers - Module

Table 10.03
Rynite ® Resins—Screw Fastening Data for “Plastite” 48°-2 Thread Rolling Screws (2)
70
Rynite ® 530 Rynite ® 545
Fail Fail
Screw Boss Hole Length at Torque Pullout Mode of Torque Pullout Mode of
Size Dia., in Size, in Engagement, in in·lb lb Failure 1 in·lb lb Failure
#4 0.313 0.101 0.313 20 730 SB/HS 24 760 SB/HS
#6 0.385 0.125 0.563 38 — HS 38 — HS
#8 0.750 0.154 0.438 57 1370 HS 71 1380 HS
#10 0.750 0.180 0.500 110 2200 HS 110 2340 SB
1 ⁄4 0.750 0.238 0.500 — 2400 HS 150 2390 HS
Rynite ® 935 Rynite ® 430
#4 0.313 0.101 0.313 19 490 HS/BC 19.5 500 HS
#6 0.385 0.125 0.563 37 — HS/BC 39 — HS
#8 0.750 0.154 0.438 55 1050 HS/BC 69 1205 HS
#10 0.750 0.180 0.500 81 1640 HS/BC 85 1725 HS
1 ⁄4 0.750 0.238 0.500 116 1730 BC 156 2010 HS
1 Failure legend: HS = Hole Stripped; BC = Boss Cracked; SB = Screw Break
2 ”Plastite’’ screws available from Continental Screw, 459 Mount Pleasant St., P.O. Box 913, New Bedford, MA 02742. Data determined by Continental Screw.
Table 10.04
Recommended “Plastite” Screws And Boss Dimensions
Length of Engagement Length of Engagement
2 x Basic Screw Diameter 3 x Basic Screw Diameter
48°-2 Minimum Approximate Minimum Approximate
“Plastite” Hole Boss Length of Hole Boss Length of
Screw Size Size, in Diameter, in Engagement, in Size, in Diameter, in Engagement, in
#4 0.098 0.281 0.250 0.101 0.281 0.343
#6 0.116 0.343 0.281 0.120 0.343 0.437
#8 0.149 0.437 0.312 0.154 0.437 0.500
#10 0.173 0.500 0.365 0.180 0.500 0.562
1 ⁄4 0.228 0.625 0.500 0.238 0.625 0.750
Notes to Tables 10.03 and 10.04
• There can be some deviations to these dimensions as 1 ⁄ 4″ size 45°-2 “Plastite” screw size in Rynite ® 530 and
545 provided a slightly better balance of performance in a 0.238″ diameter hole, 1 ⁄ 2″ engagement. However, this
chart accounts for general, not specific, application conditions.
• For tapered, cored holes, the stated hole size should be at the midlength of engagement. Draft can then be per
normal molding practice. Performance should be similar to a straight hole.
• For lengths of engagement longer than three times basic screw diameter, hole should be proportionately
enlarged.
• Data developed by Continental Screw for resins listed in Table 10.03.