Spring Tension Pin, Heavy Duty, Metric Sizes
What Is a Heavy Duty Spring Tension Pin?
A spring tension pin, also called a coiled spring pin, is manufactured by rolling a strip of spring steel into a tightly coiled cylindrical shape rather than machining it from solid bar stock. Because the coiled body compresses slightly as it's driven into a drilled hole, the pin applies continuous spring pressure against the hole wall along its full length, which resists loosening from shock, vibration, and repeated load cycling.
The heavy duty version is wound with more coil overlap than a standard spring tension pin, giving a thicker effective wall section and higher shear strength for higher load fastening, shear pin, and hinge pin applications.
Key Features and Benefits
- Coiled Spring Steel Construction: applies continuous radial spring pressure inside the hole.
- Higher Shear Strength: heavier coil overlap than standard duty pins for higher load applications.
- Vibration and Shock Resistant: spring action resists working loose under cyclic loading.
- Chamfered Ends: ease starting into a drilled hole without a lead-in reamer.
- Reusable Installation: can typically be removed and reinstalled without losing all holding force.
Materials and Finishes
- Spring Steel: rolled and heat treated for consistent coil tension and shear strength.
- Plain or Zinc Plated Finish: options depending on the corrosion resistance needed.
Standards Compliance
- ISO 8748, Heavy duty coiled spring pins
- ASME/ANSI B18.8.2, Coiled spring pins, standard duty and heavy duty
Size Range and Availability
Available in a full metric size range, sold individually or in bulk quantities.
Related Categories and Products
Frequently Asked Questions (FAQs)
1. What is a heavy duty spring tension pin used for?
It's used as a shear pin, hinge pin, or general fastening pin in applications needing high shear strength and resistance to loosening from shock or vibration.
2. How is a heavy duty spring tension pin different from a standard duty version?
The heavy duty version has more coil overlap, giving a thicker effective wall section and higher shear strength than a standard duty spring tension pin.
3. How does a coiled spring pin stay in place inside a hole?
The coiled body compresses slightly when driven into a drilled hole, applying continuous spring pressure against the hole wall along its length.
4. Can a spring tension pin be reused after removal?
Yes, in most cases it can be removed and reinstalled without fully losing its holding force, unlike a plain interference fit pin.
5. Does a spring tension pin require a reamed hole?
No, it's designed to fit a standard drilled hole rather than a precision reamed hole.
6. What sizes are available?
We stock a full metric size range, available individually or in bulk quantities.
