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Introduction to Wire Thread Inserts

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A new type of internal thread fastener. It is an embedded thread reinforcement element made of high-strength stainless steel wire. Its performance is superior to internal threads formed by direct tapping. It is used to repair or strengthen threaded holes in soft materials (such as aluminum, magnesium, plastic) to provide high strength, wear resistance and anti-loosening properties.

Product Advantages

1. Wire thread inserts are lightweight and strong, usually made of hardened stainless steel 304, with material hardness HRC43-50 and material strength generally not less than 1370Mpa.

Tensile Strength Test of Wire Thread Insert Material

2. Wire thread inserts can effectively increase the internal thread strength of light alloy (magnesium, aluminum, etc.) materials to Grade 12. At the same time, the use of wire thread inserts can make the stress of internal threads more uniform. Usually, the first thread bears 50% of the force without installing the insert.

Stress Comparison Between Standard Threaded Hole and Wire Thread Insert Hole

Standard Threaded Hole Threaded Hole with Wire Thread Insert

These two advantages allow light alloy threaded holes with wire thread inserts to adapt to high-strength bolts above Grade 8.8.

Working Method of Wire Thread Inserts

1. Drilling: Use standard taps, pay attention to diameter selection. Avoid counterbore if possible.

2. Tapping: Use correct taps to tap the base thread for the selected thread size.

3. Thread Inspection: Use gauges to inspect the base thread if needed.

4. Installation: Screw the wire thread insert directly into the base thread. The end of the insert should be screwed at least 1/4 turn below the material surface.

5. Tang Breaking: Use a tang breaker to break the tang for through holes. For wire thread inserts in blind holes, the tang can be retained if maximum screwing depth is considered.

6. Inspection: Re-inspect after removing the tang.

Note: Step 5 can be omitted for tang-free inserts

Product Installation Notes

Half Installation Position Angle & Pitch Issues Full Installation Position

The key to installation is vertical screwing, matching tools, and stopping in place

1. Positioning & Screwing: Put the insert into a special wrench, align with the tapped base hole, screw vertically to make the insert partially enter.

2. Avoid Errors: As shown in the figure, ensure the wrench is vertical to avoid skew caused by "angle issues"; use taps with matching pitch to avoid "pitch issues" that cause inability to screw or thread jumping.

3. Full Installation: As shown in the figure, screw the insert to the specified depth (usually about one pitch reserved at the hole), the tang is exposed at this time, ready for subsequent processing.

Tool Display

Installation Tools

Inspection Tools

Product Features

1. Materials include stainless steel SUS304, SUS316, phosphor bronze, and high-temperature resistant INCONEL nickel alloy.

2. Surface treatments include lubrication, tin plating, zinc plating, silver plating (for high temperature requirements), etc.

3. Sizes range from M2 to M39.

4. Threads include coarse and fine threads.

5. Lengths include 1D, 1.5D, 2D, 2.5D, 3D (5 standard specifications), customized lengths are also available.

6. Types include standard and locking.

7. Two styles: with tang and tang-free.

8. Appearance colors can be red, green, etc. as required.

Industry Applications

New Energy Vehicles

Light Alloys

Embodied Intelligence

HPC & AI Servers

Industrial Electronics

Consumer Electronics

Low-Altitude Economy

Aerospace

Wire Thread Insert Standards
Table 1 Metric Thread Tap Drill & Depth Details

Metric Coarse	Pitch	Tap Drill d	Drill Depth T	Thread Depth D	Metric Fine	Pitch	Tap Drill	Drill Depth	Thread Depth
M2.0	0.4	1.6	6	4	M2.5	0.35	2.2	6	4
M2.2	0.45	1.75	6	4	M3.5	0.35	2.7	8	6
M2.3	0.45	1.9	6	4	M4.0	0.5	3.5	9	7
M2.5	0.45	2.1	7	4.5	M4.5	0.5	4	9	7
M2.6	0.45	2.2	7	4.5	M5.0	0.5	4.5	14	11
M3.0	0.5	2.5	8	6	M5.5	0.5	5	14	11
M3.5	0.6	2.9	8	6	M6.0	0.75	5.3	15	12
M4.0	0.7	3.3	9	7	M7.0	0.75	6.3	15	12
M4.5	0.75	3.25	9	7	M8.0	1	7	18	15
M4.5	0.75	3.8	10	8	M8.0	0.75	7.3	18	15
M5.0	0.8	4.2	14	11	M8.5	0.75	7.3	18	15
M5.0	0.9	4.1	14	11	M9.0	0.75	8	18	15
M6.0	1	5	15	12	M9.0	0.75	8.3	18	15
M7.0	1	6	15	12	M10.0	1.25	8.8	20	17
M8.0	1.25	6.8	18	15	M10.0	0.75	9	20	17
M9.0	1.25	7.8	18	15	M11.0	0.75	9.3	20	17
M10.0	1.5	8.5	20	17	M11.0	1.25	10.3	20	17
M11.0	1.5	9.5	20	17	M12.0	1.25	10.8	20	17
M12.0	1.75	10.3	20	17	M12.0	1.25	10.8	20	17
M14.0	2	12	25	22	M12.0	1.25	10.8	20	17
M16.0	2	14	25	22	M14.0	1.5	12.5	25	22
M18.0	2.5	15.5	25	22	M15.0	1.5	13.5	25	22
M20.0	2.5	17.5	25	22	M16.0	1.5	14.5	25	22
M22.0	2.5	19.5	25	22	M20.0	1.5	15	25	22
M24.0	3	21	25	22	M22.0	2	18	25	22
M27.0	3	24	25	22	M24.0	2	18	25	22
M30.0	3.5	26.5	25	22	M27.0	2	16.5	25	22
M33.0	3.5	29.5	25	22	M30.0	2	16.5	25	22
M36.0	4	32	25	22	M33.0	2	16.5	25	22
M39.0	4	35	25	22	M36.0	2	16.5	25	22

Wire Thread Insert Standards
Table 2 GB/T 24425.1-2009 Parameters - (Coarse Thread)

Insert Size	Guide dy		Free Dia Dz		Nominal Length n*p	Free Coils N (min)		Installed Length
Insert Size	min	max	min	max	Nominal Length n*p	min	max	min	max
M2			2.53	2.7	1d	3	3.4	1.6	1.8
					1.5d	5.3	5.6	2.6	2.8
					2d	7.6	7.9	3.6	3.8
					2.5d	9.9	10.2	4.6	4.8
					3d	12.2	12.4	5.5	5.8
M2.5			3.2	3.7	1d	3.3	3.8	2.05	2.375
					1.5d	5.9	6.3	3.3	3.525
					2d	8.5	8.8	4.55	4.775
					2.5d	11.1	11.4	5.8	6.025
					3d	13.6	13.9	7.05	7.275
M3			3.8	4.35	1d	3.6	4.3	2.5	2.75
					1.5d	6.3	7.1	4	4.25
					2d	9	9.8	5.5	5.75
					2.5d	11.8	12.6	7	7.25
					3d	14.5	15.3	8.5	8.75
M4			5.05	5.6	1d	3.6	4.2	3.3	3.65
					1.5d	6.3	6.9	5.3	5.65
					2d	9.1	9.5	7.3	7.65
					2.5d	11.8	12.2	9.3	9.65
					3d	14.4	14.9	11.3	11.65
M5			6.25	6.8	1d	4	4.7	4.2	4.6
					1.5d	6.8	7.6	6.7	7.1
					2d	9.6	10.6	9.2	9.6
					2.5d	12.4	13.5	11.7	12.1
M6	7.28	7.58	7.58	7.95	1d	3.8	4.5	5	5.5
					1.5d	6.5	7.3	8	8.5
					2d	9.2	10.2	11	11.5
					2.5d	12	13	14	14.5
					3d	14.6	15.8	17	17.5
M7	8.28	8.58	8.58	9.2	1d	4.7	5.4	6	6.5
					1.5d	7.9	8.8	9.5	10
					2d	11	12.1	13	13.5
					2.5d	14.2	15.4	16.5	17
					3d	17.3	18.7	20	20.5
M8	9.55	9.85	9.85	10.35	1d	4.4	4.9	6.75	7.375
					1.5d	7.3	8	10.75	11.375
					2d	10.3	11.1	14.75	15.375
					2.5d	13.3	14.1	18.75	19.375
					3d	16.4	17.2	22.75	23.375
M10	11.82	12.1	12.1	12.8	1d	4.7	5.2	8.5	9.25
					2d	11	11.6	18.5	19.25
					2.5d	14.2	14.8	23.5	24.25
					3d	17.3	18	28.5	29.25
M12	14.2	14.5	14.5	15	1d	4.8	5.4	10.25	11.125
					1.5d	8.1	8.7	16.25	17.125
					2d	11.3	12	22.25	23.125
					2.5d	14.6	15.3	28.25	29.125
					3d	17.8	18.6	34.25	35.125
M14	16.47	16.87	16.87	17.87	1d	4.9	5.5	12	13
					1.5d	8.3	8.9	19	20
					2d	11.6	12.3	26	27
					2.5d	14.9	15.6	33	34
					3d	18.2	19	40	41
M16	18.67	18.87	18.87	19.9	1d	6	6.5	14	15
					1.5d	9.8	10.3	22	23
					2d	13.6	14.2	30	31
					2.5d	17.4	18	38	39
M18	21	21.4	21.4	22	1d	5.2	6.1	15.5	16.75
					1.5d	8.6	9.5	24.5	25.75
					2d	12.1	13	33.5	34.75
					2.5d	15.5	16.5	42.5	43.75
					3d	18.9	20	51.5	52.75
M20	23.01	23.46	23.46	24.4	1d	6	6.8	17.5	18.75
					1.5d	9.7	10.7	27.5	28.75
					2d	13.5	14.6	37.5	38.75
					2.5d	17.3	18.4	47.5	48.75
					3d	21.2	22.3	57.5	58.75
M22	25.01	25.61	25.61	26.9	1d	6.7	7.6	19.5	20.75
					1.5d	10.9	11.9	30.5	31.75
					2d	15.1	16.1	41.5	42.75
					2.5d	19.3	20.4	52.5	53.75
					3d	23.5	24.6		64.75
M24	27.55	28.15	28.15	29.1	1d	6	6.7	21	22.5
					2.5d	17.4	18.3	57	58.5
					3d	21.3	22.2	69	70.5
M27	30.55	31.15	31.15	32.4	1d	6.9	7.7	24	25.5
					1.5d	11.1	12.2	37.5	39
					2d	15.5	16.7		52.5
					2.5d	19.3	20.4	64.5	66
					3d	23.9	24.7	78	79.5
M30	34.1	34.7	34.7	35.81	1d	6.5	7.1	26.5	28.25
					1.5d	10.6	11.3	41.5	43.25
					2d	14.4	15.4	56.5	58.25
					2.5d	18.7	19.2	71.5	73.25
					3d	22.8	23.4	86.5	88.25
M33	37.09	37.7	37.7	39.01	1d	7.3	8.2	29.5	31.25
					1.5d	11.8	12.9	46	47.75
					2d	16.3	17.6	62.5	64.25
					2.5d	20.8	21.3	79	80.75
M36	40.63	41.33	41.33	42.67	1d	6.9	7.5	32	34
					1.5d	11.2	11.9	50	52
					2d	15.5	16.3	68	70
					2.5d	19.7	20.3	86	88
					3d	24	24.6	104	106
M39	43.63	44.33	44.33	45.75	1d	7.7	8.3	35	37
					1.5d	12.3	13	54.5	56.5
					2d	17	17.7	74	76
					2.5d	21.6	22.1	93.5	95.5
					3d	26.2	26.8	113	115

Custom Special Wire Thread Inserts
Table 3 Custom Special Parameters - (Coarse Thread)

Insert Size	Nominal Length n*p	Coils N	Free Dia Dz	Color	Tang / Tang-Free
M4	1d	3.6-4.2	5.05-5.6	Green	With Tang
M4	3d	14.4-14.9	5.05-5.6	Natural	With Tang
M5	1.5d	6.8-7.6	6.25-6.80	Red	Blind Hole, 65% Slot
	1.5d	6.75-7.25	6.28-6.8	Green	With Tang
	1.5d	6.8-7.6	6.15-6.54	Green	With Tang
	1.5d	/	/	Natural	Tang-Free
	2d	9.45-9.7	6.35-6.6	Green	With Tang
	2d	9.6-10.6	6.35-6.4	Natural	With Tang
	2d	/	/	Natural	Tang-Free
M6	1.5d	6.5-7.3	7.5-7.55	Natural	With Tang
M6	2d	9.2-10.2	7.5-7.55	Natural	With Tang
M7	1d	/	/	Natural	With Tang
M7	1.5d	/	/	Red	With Tang
M8	1d	4.55-4.9	9.7-9.8	Natural	Tang-Free
	1.5d	7.3-8.0	9.85-10.35	Natural	With Tang
	2d	10.3-11.1	9.85-10.35	Natural	With Tang
	2.5d	13.3-14.1	9.85-10.35	Green	With Tang
M10	1.5d	7.8-8.4	12.1-12.8	Green	With Tang
	2d	11-11.6	12.1-12.8	Green	With Tang
	3d	20.2-21.6	11.87-12.65	Green	With Tang

Note: See this diagram for Table 2 & Table 3

Wire Thread Insert Standards
Table 4 GJB 119.4A-2001 Parameters

Pitch P (mm)	B Basic (mm)	B Upper (μm)	B Lower (μm)	K1 Basic (mm)	K Lower (μm)	K2 Basic (mm)	K2 Lower (μm)	A min (mm)
0.4	0.26	0	-10	0.26	-50	0.217	-20	0.32
0.45	0.292		-10	0.292	-50	0.244	-20	0.36
0.5	0.325	0	-10	0.325	-60	0.271	-25	0.4
0.7	0.455	0	-10	0.455	-60	0.379	-25	0.56
0.8	0.52	0	-12	0.52	-60	0.433	-40	0.64
1	0.65	0	-12	0.65	-90	0.541	-40	0.8
1.25	0.812	0	-12	0.812	-90	0.677	-55	1
1.5	0.974	0	-13	0.974	-120	0.812	-55	1.2
1.75	1.137	0		1.137	-120	0.947	-70	1.4
2	1.299	0	-13	1.299	-120	1.083	-70	1.6
2.5	1.624	0	-13	1.624	-160	1.353	-100	2
3	1.949	0	-13	1.949	-160	1.624	-100	2.4
3.5	2.273	0	-13		-200	1.894	-120
4	2.598	0	-13	2.598	-200	2.165		3.2

Industry Challenges & Solutions

Project Cycle Cost Influence Model

In today's rapidly developing society, the core challenge for enterprise R&D is: the early decision window is extremely short but locks most of the cost; while the later stage has huge investment but extremely high error correction costs, leading to serious mismatch between risks and benefits. This requires enterprises to make accurate judgments at the very early stage to cope with market uncertainty.

15-85 Rule

Excessive focus on explicit procurement costs while ignoring 85% of hidden costs leads to lack of systematic coordination in design, supply chain, after-sales and other links, greatly increasing the total life cycle cost.

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Summary

As a high-performance internal thread reinforcement component, wire thread inserts are widely used in industrial fields with high requirements for thread strength, wear resistance and reliability. Through standardized installation technology and diversified specifications, it can perfectly solve industry pain points such as insufficient thread strength, easy damage and easy loosening of soft materials, effectively improve the overall stability and service life of equipment, and is the preferred solution for modern industrial fastening connections.

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