Carbon Steel Grade 8 Castle Nuts with Cotter Pins 5/8-18 Crown Nut Hex with Groove

Beschrijving

What are Castle Nuts with Cotter Pins?

Castle nuts with cotter pins are a secure fastening system designed to prevent loosening under vibration or dynamic loads. The castle nut (a slotted nut) pairs with a cotter pin (a bent metal pin) that inserts through both the nut’s slots and a cross-drilled hole in the bolt, creating a positive mechanical lock. This assembly ensures the nut cannot rotate off without removing the pin.

Materials

Castle Nuts

1. Carbon Steel (Grade 5/8) – High strength for automotive/industrial use.

2. Stainless Steel (304/316) – Corrosion-resistant for marine/outdoor applications.

3. Alloy Steel (AISI 4140) – Heat-treated for extreme loads (e.g., heavy machinery).

4. Brass – Non-sparking, used in plumbing/electrical systems.

5. Aluminum – Lightweight (aerospace applications).

Cotter Pins

1. Stainless Steel (302/304) – Rust-proof for harsh environments.

2. Carbon Steel – Zinc-plated for general use.

3. Monel – High corrosion resistance (marine/chemical industries).

4. Bronze – Non-magnetic and wear-resistant.

Surface Treatments

• Castle Nuts:

  • Zinc plating (most common).

  • Hot-dip galvanizing (for outdoor/marine use).

  • Black oxide (military/aerospace).

  • Passivation (stainless steel).

• Cotter Pins:

  • Zinc plating (basic corrosion resistance).

  • Stainless steel (natural finish, no coating needed).

Specifications

• Thread Sizes: #10 to 1½” (UNC/UNF or metric).

• Nut Height: Taller than standard nuts to fit cotter pins.

• Pin Diameters: 1/16″ to 1/4″ (matched to bolt hole size).

• Standards:

  • DIN 935 / ISO 7035 (castle nuts).

  • ASTM F594 (cotter pins).

  • MIL-SPEC (for defense applications).

Applications Castle Nuts with Cotter Pins

• Automotive: Wheel bearings, suspension linkages.

• Aerospace: Flight control systems, landing gear.

• Industrial Machinery: Rotating shafts, hydraulic cylinders.

• Rail/Marine: Securing critical bolted joints.

• Agriculture: Tractor/implement assemblies.

Excellent Case: Aircraft Landing Gear Assembly

Challenge: A commercial aircraft manufacturer needed to ensure the landing gear pivot bolts remained secure despite constant vibration and shock loads during takeoff/landing.

Solution:

• Used AISI 4140 alloy steel castle nuts (heat-treated) with stainless steel cotter pins.

• Precision-drilled bolt holes to ensure perfect pin alignment.

• Applied black oxide coating for corrosion resistance.

Result:

• Zero Incidents: No reported loosening in 10+ years of fleet operation.

• FAA Compliance: Met strict aviation safety standards (FAR 25.607).

• Maintenance Efficiency: Quick visual inspection confirmed pin integrity.