Premium Quality High Tensile Steel Wire Screw Thread Inserts for Structural Fastening

M33-M60 Repair Thread Size Conversion SUS304 Inserts

Product Name:Metric M33-M60 Wire Thread Inserts
Brand Name: KernalCoil Thread Insert
Material: Stainless steel 304/customized material
Customized Support: OEM, ODM, OBM
Quality Control: Range Inspection, Test Report
Place of Origin: Shenzhen, China
Application：Automotive/Die-casting/Aerospace/Rail transportation/Marine etc.
Function: Repairing threads/converting threads/assembling products
Low Abrasion: High hardness,it has little wear and tear in connection with screw. Long service time, reusable
Rust Resistance: Made of 304 stainless steel. anti-oxidation layer is formed on the surface. rust-proof and Anti-corrosion
Anti-loose: With certain elastic and even load,eliminate the screw and screw hole deviation between the pitch and tooth type and absorb vibration
Easy to use: The damaged screw holes shall be put into the wire screw sleeve without increasing the diameter of the screw hole

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Detail

The wire coil insert, or thread insert, is made of high-strength, high-precision, low-roughness, corrosion-resistant rhombic-cross section stainless steel wire, wound like a spring. When screwed into a threaded hole, its outer surface clings to the hole by elastic force, and the inner surface forms a standard thread.

This insert improves threaded connection strength and wear resistance, creates an elastic connection, and evens out thread load distribution. It reduces stress on the first 1-2 threads near the section, preventing bolt breakage and thread - tooth wear.

Tests show that the load on the first thread of a common connection is higher than that with an insert (40% - 50% higher for aluminum housings and 70% - 75% for steel ones). After using the insert, the load on the first few threads decreases while that on the last few increases, and the load can still be transmitted.

Made from 1Cr18Ni9Ti stainless steel wire by cold - rolling, the insert cuts screw - friction torque by 90%, allowing for maximum pre-tightening with minimum effort and preventing loosening. In high-temperature areas, it reduces thermal stress and prevents seizing or galling.

Using the insert enables choosing smaller, stronger screws under the same strength conditions, saving materials, reducing weight, and shrinking volume. It can also quickly repair processing errors or stripped threads, with performance superior to original tapped threads. Additionally, it's convenient for metric-inch conversion.

1. Aerospace & Defense
Applications: Fastening in engine components, avionics, landing gear, and structural assemblies.

Advantages:
High Strength-to-Weight Ratio: Enables lightweight designs while meeting stringent load requirements.
Vibration Resistance: Prevents thread loosening under extreme dynamic loads.
Corrosion Resistance: Compatible with titanium or stainless steel substrates in harsh environments.

Key Parameters:
Material: Stainless steel (ASTM A313), Inconel® (for high-temperature zones).
Temperature Range: -200°C to +800°C.
Thread Standards: UNJF, MJ, or custom specifications per MIL-SPEC/AMS standards.

2. Automotive & Motorsports

Applications: Engine blocks, transmission systems, brake calipers, and high-performance racing components.

Advantages:

Thread Repair: Restores damaged threads in aluminum/magnesium housings cost-effectively.
Fatigue Life Extension: Reduces wear in frequently disassembled joints.
Thermal Stability: Maintains clamp load under cyclic thermal stresses.
Key Parameters:
Installation Torque: 10–25 N·m (varies by insert size and substrate).
Coating Options: Zinc-nickel or dry-film lubricants for corrosion protection.
Standards: SAE AS8879, ISO 9001-compliant manufacturing.
3. Industrial Machinery
Applications: Hydraulic systems, CNC equipment, and heavy-duty bolted joints.
Advantages:
Load Distribution: Reduces stress concentration in soft substrates (e.g., cast iron, plastics).
Maintenance Reduction: Eliminates thread stripping in high-cycle applications.
Chemical Resistance: Suitable for oil, coolant, and acidic environments.
Key Parameters:
Shear Strength: Up to 1,200 MPa (dependent on insert grade).
Thread Sizes: M3–M48, UNC/UNF/Metric.
Installation Tools: Manual or pneumatic insertion tools.
4. Electronics & Microengineering
Applications: Precision connectors, semiconductor manufacturing tools, and micro-optics.
Advantages:
Miniaturization: Enables reliable threads in thin-walled or brittle materials (e.g., ceramics).
EMI Shielding: Conductive inserts enhance grounding in RF assemblies.
Key Parameters:
Thread Sizes: M1–M2.5, #0-80 to #2-56.
Conductive Coatings: Silver-plated options available (per MIL-DTL-45204).

Thread Specification *DiameterPitch**	Installed Length *kd**	Installed Length L(mm)	Number of Turns before Installation N(≈)	Outer Diameter before Installation (mm)	Drill Diameter do (mm)
M33*3.5	1d	33	7.8	38.1-38.6	33.9
	1.5d	49.5	12.2
	2d	66	16.6
	2.5d	82.5	21.1
	3d	99.0	25.5
M33*2	0.5d	16.5	6.4	38.0-38.5	33.5
	0.75d	24.8	10.1
	1d	33.0	13.8
	1.5d	49.5	21.2
M33*1.5	0.5d	16.5	8.7	37.8-38.3	33.4
	0.75d	24.8	13.6
	1d	33.0	18.5
M36*4	0.75d	27.0	5.2	41.9-42.3	37
	1d	36.0	3.7
	1.5d	54.0	11.6
	2d	72.0	15.8
M36*3	0.5d	18.0	4.4	41.8-42.3	36.8
	0.75d	27.0	7.1
	1d	36.0	9.9
	1.5d	54.0	15.4
M36*2	0.5d	18.0	6.9	41.7-42.3	36.5
	0.75d	27.0	11
	1d	36.0	15
	1.5d	54.0	23
M39*2	0.5d	19.5	7.7	44.8-45.4	39.5
	0.75d	29.3	12.1
	1d	39.0	16.4
M42*4.5	1d	42.0	7.3	49-51	43
	1.25d	52.0	9.5
	1.5d	63.0	11.6
M42*3.0	1d	42.0	11.7	48-50.5	43
	1.25d	52.0	14.8
	1.5d	63.0	18.1
M48*3.0	0.5d	24.0	6.2	55-55.5	48.8
	0.75d	36.0	9.9
	1d	48.0	13.6
M56*4.0	0.5d	28.0	5.4	64-65	17
	0.75d	42.0	8.6
	1d	56.0	11.8
M60*3.0	0.5d	30.0	7.9	69-70	60.8
	0.75d	45.0	12.4
	1d	60.0	16.9
	1.5d	90.0	25.9
M60*4.0	0.5d	30.0	5.8	69-70	61
	0.75d	45.0	9.8
	1d	60.0	12.6
	1.5d	90.0	19.5