Coiled Spring Pins
ISO 8748, BS 7057, DIN 7344, ISO 8750, BS 7058, DIN 7343
Coiled spring pinss consist of 2-1/4 coils of spring steel or stainless steel and have swaged chamfers at each end. They are designed for plain drilled holes, but countersinking makes insertion easier.
Torqbolt Coiled Spring Pins are available in either standard duty (ISO 8750) or heavy duty (ISO 8748) to provide options for strengths, flexibility and diameter.
Heavy Duty: ISO 8748 / BS 7057 / DIN 7344, typically used in high shear strength applications and hardened host materials.
Standard Duty: ISO 8750 / BS 7058 / DIN 7343, offer the best balance between flexibility and strength and are recommended for most applications.
Advantages of Coiled Spring Pin
- The Coiled design improves shock absorption as the load is spread over more than one coil.
- Assembly is easier as the insertion force needed is lower.
- The pins cannot interlock when in bulk, which is a benefit when they are to be barrel plated or installed using bowl-fed equipment.
Coiled Spring Pin Finishes
Coiled Spring Pins are normally supplied with a plain oiled finish. Steel pins may be given a protective finish such as zinc, phosphate, etc but for electrolytically applied finishes it is essential to de-embrittle the pins immediately after plating. Since the de-embrittlement process is not completely reliable, non-electrolytic finishes or stainless should be used for safety-critical applications. Where pins are to be used in plastic assemblies, it is recommended that they be de-oiled before use to avoid embrittlement of the plastic.
| Nominal Diameter, mm | 0.8 | 1 | 1.2 | 1.5 | 2 | 2.5 | 3 | 3.5 | 4 | 5 | 6 | 8 | 10 | 12 | 14 | 16 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Expanded Diameter | |||||||||||||||||
| ISO 8750 | Min | 0.85 | 1.05 | 1.25 | 1.62 | 2.13 | 2.65 | 3.15 | 3.67 | 4.2 | 5.25 | 6.25 | 8.3 | 10.35 | 12.4 | 14.45 | 16.45 |
| Max | 0.91 | 1.15 | 1.35 | 1.73 | 2.25 | 2.78 | 3.3 | 3.84 | 4.4 | 5.5 | 6.5 | 8.63 | 10.8 | 12.85 | 14.95 | 17 | |
| ISO 8748 | Min | 1.61 | 2.11 | 2.62 | 3.12 | 3.64 | 4.15 | 5.15 | 6.18 | 8.25 | |||||||
| Max | 1.71 | 2.21 | 2.73 | 3.25 | 3.79 | 4.3 | 5.35 | 6.4 | 8.55 | ||||||||
| Recommended Min | Min | 0.8 | 1 | 1.2 | 1.5 | 1.99 | 2.49 | 2.99 | 3.48 | 3.98 | 4.95 | 5.95 | 7.93 | 9.93 | 11.9 | 13.85 | 15.85 |
| Hole Size | Max | 0.84 | 1.04 | 1.24 | 1.6 | 2.1 | 2.6 | 3.1 | 3.62 | 4.12 | 5.12 | 6.13 | 8.17 | 10.2 | 12.22 | 14.25 | 16.25 |
| Minimum Double Shear Strengths-Tested to ISO 8749, kN |
|||||||||||||||||
| Spring Steel (ISO 8750) | 1.45 | 2.5 | 3.9 | 5.5 | 7.5 | 9.6 | 15 | 22 | 39 | 62 | 89 | 120 | 160 | ||||
| Spring Steel (ISO 8748) | 1.9 | 3.5 | 5.5 | 7.6 | 10 | 13.5 | 20 | 30 | 53 | 30 | |||||||
| Stainless Steel (ISO 8750) | 1.05 | 1.9 | 2.9 | 4.2 | 7.6 | 11.5 | 16.8 | 30 | 30 | ||||||||
Coiled Spring Pin Materials
- Spring Steel
- Austenitic Stainless Steel
Forging Specifications
ASTM A105 ASTM A1099 ASTM A181 ASTM A182 ASTM A266 ASTM A336 ASTM A350 ASTM A522 ASTM A541 ASTM A582 ASTM A592 ASTM A638 ASTM A694 ASTM A705 ASTM A707 ASTM A727 ASTM A836 ASTM A965 ASTM B124 ASTM B381 ASTM B462 ASTM B493 ASTM B564 ASTM B637 ASTM B865Bar Stock Specifications
ASTM A108 ASTM A276 ASTM A29 ASTM A36 ASTM A479 ASTM A529 ASTM A564 ASTM A572 ASTM A576 ASTM B103 ASTM B121 ASTM B122 ASTM B134 ASTM B139 ASTM B150 ASTM B151 ASTM B16 ASTM B160 ASTM B164 ASTM B166 ASTM B169 ASTM B335 ASTM B348 ASTM B36 ASTM B365 ASTM B387 ASTM B408 ASTM B425 ASTM B446 ASTM B473 ASTM B550 ASTM B572 ASTM B574 ASTM B805 ASTM B927 ASTM B98 ASTM B99Material
Alloy Steel Coiled Spring Pin Aluminium Alloy Coiled Spring Pin Aluminum Bronze Coiled Spring Pin Berylium Copper Coiled Spring Pin Carbon Steel Coiled Spring Pin Cobalt Alloy Coiled Spring Pin Copper Nickel Coiled Spring Pin Duplex Steel Coiled Spring Pin Hastelloy Coiled Spring Pin Incoloy Coiled Spring Pin Inconel Coiled Spring Pin Maraging Steel Coiled Spring Pin Molybdenum Coiled Spring Pin Monel Coiled Spring Pin Nickel Alloy Coiled Spring Pin Nimonic Coiled Spring Pin Nitronic Coiled Spring Pin Phosphor Bronze Coiled Spring Pin Silicon Bronze Coiled Spring Pin Stainless Steel Coiled Spring Pin Stellite Coiled Spring Pin Super Duplex Stainless Steel Coiled Spring Pin Tantalum Coiled Spring Pin Titanium Coiled Spring Pin Zeron 100 Coiled Spring Pin Zirconium Coiled Spring PinMaterial Grades
- Carbon Steel 1018, 1020, 1040, 1045
- Alloy Steel 4130, 4140, 4142, 4340, 6150, 8620
- Chrome Moly Steel 25CRMO4, 21CRMOV5-7, 42CRMO4, 42CRMOV4-6
- Austenitic Stainless Steel 301, 302, 303, 304, 316, 317, 321, 310, 309, 329, 347 & 348
- Martensitic / Ferritic Stainless Steel 403, 405, 409, 410, 414, 416, 418, 420 & 430F
- Super Austenitic Stainless Steel 904l, 254-Smo, 253Ma, Alloy 20, Sanicro Alloy 28, Al-6xn, 310Moln, Alloy 230, Alloy 330 , Alloy 333
- Precipitation Hardening Stainless Steel Alloy A-286, A453 GRADE 660, 17-4 PH, 15-5 Ph , 15-7 Ph, 17-7 Ph
- Nitronic 50 , 60 ( xm-19), 30, 32, 33, 40
- Duplex 32205 (F60), 31803 (F51);Super Duplex 32750 ( F53) , 32760 (Zeron 100), (F55), 329, Ferralium 255, 255FG46
- Inconel 600, 601, 602, 603, 617, 625, 686, 702, 713, 718, 725, 738, 740, 783, X-750, 701, 901, 939
- Incoloy 800, 800H, 800HT, 825, 925, 926, 945
- Hastelloy C276, C22,C-2000,C4,B, B2, B3, G30, X, N
- Monel Alloy 400, K-500, R405
- Nimonic Alloy 80A, 90, 105, 115, 263
- Titanium Grade1, 2, 3, 4, 5, 6, 7,8, 9, 11, 12, 19,23
- Nickel 200, 201
- Copper Nickel 70/30, 90/10
- Silicon Bronze C651, C655, C656
- Cobalt Alloys Invar 36 / 42, Waspalloy, MP35N / 159, Stellite 3/6/12/21, Rene 41, L605
- Molybdenum Grade 361/363/364/365
- Durehete 900/950/1055, JETHETE X19/M152, Hiduron 130/190, Tantalum, Zircoloy, Aluminium Alloy 2024, 6061, 7075