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Helical Inserts: 3-56, 0.297" (3.0xD) Length, Locking (100 pcs)
Part Number 84903
Helical Inserts: 3-56, 0.297" (3.0xD) Length, Locking (100 pcs)
Helical Thread Inserts: 3-56, 0.297" (3.0xD) Length, Locking, Package of 100
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Product Specs:
  • Internal Thread Size: 3-56 UNF
  • Length: 0.297" (3x diameter)
  • Material: 18-8 (304) Stainless Steel
  • Type: Locking
  • Tap Size: 3-56 STI
  • Drill Size: #37
  • Package Quantity: 100
Quickly and easily repair stripped or damaged threads, or create stronger original threads in die castings or plastics with our Helical Screw Thread Inserts.  Coil tension securely holds the insert in place without undue tension on the surrounding material.  The inserts are vibration and impact resistant.  Made from corrosion resistant stainless steel, they offer a wide temperature tolerance.

Helical Locking Inserts have an internal locking thread that grips the bolt and prevents loosening from vibration or impact.  One or more coils of the insert have a series of straight segments or chords that achieve locking action.  Locking Inserts have a high reusable factor allowing frequent removal and reassembly of bolt without appreciable loss of torque.  The internal locking mechanism eliminates the need for lock wiring, lock nuts, lock washers, chemical compounds and other additional tools/substances.  Helical Locking Inserts are often used in Automotive, Military, Electronics, Industrial, Aviation, and Aerospace applications.

Helical Inserts are often known by the brand names Helicoil or Recoil Screw Thread Inserts.  Our Precision Thread Helical Inserts are interchangeable with other brands of inserts and tooling.  If you are currently using Helicoil, Recoil, or Mil Spec part numbers for your inserts, please see our Cross Reference Numbers below for an easy and accurate transition to our Precision Thread Helical Inserts from Chrislynn.

Cross Reference: Helical Insert, 3-56, 0.297" (3.0xD) Length, Locking
  • Chrislynn P/N: 84903
  • Helicoil P/N: 3591-03CN-0297
  • Recoil P/N: 14536
  • Mil-Spec P/N: MS21209-F0330
Available Modifications to our Helical Inserts...
  • Material - Inconel X750, Phosphor-Bronze, Nitronic 60, 316 Stainless Steel
  • Coatings - Dry Film, Cadmium, Silver Plating
  • Please call for quote & lead time for any modifications
Our Precision Thread Helical Inserts meet or exceed most applicable specifications, including: MS 122076 series, 124651 series, 21208, 21209, 33537, Mil-1-8846, and Mil-F-5577.

Not the correct size? Looking for a different length?

For a comprehensive list of our available sizes and lengths, please visit our
Helical Thread Insert summary page.

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