ISO 724 Metric Screw Threads – Basic Dimensions & Tap Drill Guide

Thread Symbols & Terminology

Symbol	Definition
D, d	Major Diameter (Nominal Diameter) – The largest diameter of the thread
P	Pitch – Distance between corresponding points on adjacent threads (mm)
D₂, d₂	Pitch Diameter – Diameter where thread width equals space width (mm)
D₁	Internal Thread Minor Diameter – Smallest diameter of internal thread with flat crest (mm)
d₃	External Thread Minor Diameter – Smallest diameter of external thread with rounded root (mm)

ISO 724 Calculation Formulas

Parameter	Formula
Pitch Diameter	D₂ = d₂ = d – 0.649519 × P
Internal Minor Diameter	D₁ = d – 1.082532 × P
External Minor Diameter	d₃ = d – 1.226869 × P

Tap Drill Size Logic

Selecting the correct tap drill size is critical for creating strong, reliable internal threads. The tap drill determines how much material remains for the tap to form threads.

Concept	Explanation
Thread Engagement %	Percentage of full thread height that actually engages between bolt and tapped hole. 75% engagement provides optimal strength with reasonable tapping torque.
Standard Formula	Tap Drill ≈ d – P
Example: M8×1.25	Tap Drill = 8.0 – 1.25 = 6.75mm  →  Use 6.8mm drill
Why This Works	This formula provides approximately 75% thread engagement, which is the engineering standard for optimal strength-to-effort ratio. Below 60% engagement risks stripping; above 90% increases tapping difficulty without significant strength gain.

Important Notes for Tap Drill Selection

• Material Consideration: Harder materials (steel, stainless) may require slightly larger drill for easier tapping. Softer materials (aluminum, brass) can use standard or slightly smaller drill.

• Drill Size Availability: The calculated size may not exist as a standard drill. Choose the closest available drill size (typically round up 0.05-0.1mm).

• Blind Holes: Drill depth must be: Thread depth + 1.5×Pitch + Drill point depth (approx. 0.3×Drill diameter).

• Thread Designation: Format is M[diameter]×[pitch]. Example: M10×1.5 means 10mm nominal diameter with 1.5mm pitch. When pitch is not specified, coarse pitch (first listed) is assumed.

Metric Screw Threads – Basic Dimensions & Tap Drill Table

Thread Size	Pitch P (mm)	Thread Type	Pitch Dia. D2 d₂ (mm)	Int. Minor D₁ (mm)	Ext. Minor d₃ (mm)	Tap Drill (mm)
M1	0.25	Coarse	0.838	0.729	0.693	0.75
M1	0.2	Fine	0.870	0.783	0.755	0.80
M1.1	0.25	Coarse	0.938	0.829	0.793	0.85
M1.1	0.2	Fine	0.970	0.883	0.855	0.90
M1.2	0.25	Coarse	1.038	0.929	0.893	0.95
M1.2	0.2	Fine	1.070	0.983	0.955	1.00
M1.4	0.3	Coarse	1.205	1.075	1.032	1.10
M1.4	0.2	Fine	1.270	1.183	1.155	1.20
M1.6	0.35	Coarse	1.373	1.221	1.171	1.25
M1.6	0.2	Fine	1.470	1.383	1.355	1.40
M1.8	0.35	Coarse	1.573	1.421	1.371	1.45
M1.8	0.2	Fine	1.670	1.583	1.555	1.60
M2	0.4	Coarse	1.740	1.567	1.509	1.60
M2	0.25	Fine	1.838	1.729	1.693	1.75
M2.2	0.45	Coarse	1.908	1.713	1.648	1.75
M2.2	0.25	Fine	2.038	1.929	1.893	1.95
M2.5	0.45	Coarse	2.208	2.013	1.948	2.05
M2.5	0.35	Fine	2.273	2.121	2.071	2.15
M3	0.5	Coarse	2.675	2.459	2.387	2.50
M3	0.35	Fine	2.773	2.621	2.571	2.65
M3.5	0.6	Coarse	3.110	2.850	2.764	2.90
M3.5	0.35	Fine	3.273	3.121	3.071	3.15
M4	0.7	Coarse	3.545	3.242	3.141	3.30
M4	0.5	Fine	3.675	3.459	3.387	3.50
M4.5	0.75	Coarse	4.013	3.688	3.580	3.75
M4.5	0.5	Fine	4.175	3.959	3.887	4.00
M5	0.8	Coarse	4.480	4.134	4.019	4.20
M5	0.5	Fine	4.675	4.459	4.387	4.50
M5.5	0.5	Coarse	5.175	4.959	4.887	5.00
M6	1	Coarse	5.350	4.917	4.773	5.00
M6	0.75	Fine	5.513	5.188	5.080	5.25
M7	1	Coarse	6.350	5.917	5.773	6.00
M7	0.75	Fine	6.513	6.188	6.080	6.25
M8	1.25	Coarse	7.188	6.647	6.466	6.75
M8	1	Fine	7.350	6.917	6.773	7.00
M8	0.75	Fine	7.513	7.188	7.080	7.25
M9	1.25	Coarse	8.188	7.647	7.466	7.75
M9	1	Fine	8.350	7.917	7.773	8.00
M9	0.75	Fine	8.513	8.188	8.080	8.25
M10	1.5	Coarse	9.026	8.376	8.160	8.50
M10	1.25	Fine	9.188	8.647	8.466	8.75
M10	1	Fine	9.350	8.917	8.773	9.00
M10	0.75	Fine	9.513	9.188	9.080	9.25
M11	1.5	Coarse	10.026	9.376	9.160	9.50
M11	1	Fine	10.350	9.917	9.773	10.00
M11	0.75	Fine	10.513	10.188	10.080	10.25
M12	1.75	Coarse	10.863	10.106	9.853	10.25
M12	1.5	Fine	11.026	10.376	10.160	10.50
M12	1.25	Fine	11.188	10.647	10.466	10.75
M12	1	Fine	11.350	10.917	10.773	11.00
M14	2	Coarse	12.701	11.835	11.546	12.00
M14	1.5	Fine	13.026	12.376	12.160	12.50
M14	1	Fine	13.350	12.917	12.773	13.00
M15	1.5	Coarse	14.026	13.376	13.160	13.50
M15	1	Fine	14.350	13.917	13.773	14.00
M16	2	Coarse	14.701	13.835	13.546	14.00
M16	1.5	Fine	15.026	14.376	14.160	14.50
M16	1	Fine	15.350	14.917	14.773	15.00
M17	1.5	Coarse	16.026	15.376	15.160	15.50
M17	1	Fine	16.350	15.917	15.773	16.00
M18	2.5	Coarse	16.376	15.294	14.933	15.50
M18	2	Fine	16.701	15.835	15.546	16.00
M18	1.5	Fine	17.026	16.376	16.160	16.50
M18	1	Fine	17.350	16.917	16.773	17.00
M20	2.5	Coarse	18.376	17.294	16.933	17.50
M20	2	Fine	18.701	17.835	17.546	18.00
M20	1.5	Fine	19.026	18.376	18.160	18.50
M20	1	Fine	19.350	18.917	18.773	19.00
M22	2.5	Coarse	20.376	19.294	18.933	19.50
M22	2	Fine	20.701	19.835	19.546	20.00
M22	1.5	Fine	21.026	20.376	20.160	20.50
M22	1	Fine	21.350	20.917	20.773	21.00
M24	3	Coarse	22.051	20.752	20.319	21.00
M24	2	Fine	22.701	21.835	21.546	22.00
M24	1.5	Fine	23.026	22.376	22.160	22.50
M24	1	Fine	23.350	22.917	22.773	23.00
M25	2	Coarse	23.701	22.835	22.546	23.00
M25	1.5	Fine	24.026	23.376	23.160	23.50
M25	1	Fine	24.350	23.917	23.773	24.00
M26	1.5	Coarse	25.026	24.376	24.160	24.50
M27	3	Coarse	25.051	23.752	23.319	24.00
M27	2	Fine	25.701	24.835	24.546	25.00
M27	1.5	Fine	26.026	25.376	25.160	25.50
M27	1	Fine	26.350	25.917	25.773	26.00
M28	2	Coarse	26.701	25.835	25.546	26.00
M28	1.5	Fine	27.026	26.376	26.160	26.50
M28	1	Fine	27.350	26.917	26.773	27.00
M30	3.5	Coarse	27.727	26.211	25.706	26.50
M30	3	Fine	28.051	26.752	26.319	27.00
M30	2	Fine	28.701	27.835	27.546	28.00
M30	1.5	Fine	29.026	28.376	28.160	28.50
M30	1	Fine	29.350	28.917	28.773	29.00
M32	2	Coarse	30.701	29.835	29.546	30.00
M32	1.5	Fine	31.026	30.376	30.160	30.50
M33	3.5	Coarse	30.727	29.211	28.706	29.50
M33	3	Fine	31.051	29.752	29.319	30.00
M33	2	Fine	31.701	30.835	30.546	31.00
M33	1.5	Fine	32.026	31.376	31.160	31.50
M36	4	Coarse	33.402	31.670	31.093	32.00
M36	3	Fine	34.051	32.752	32.319	33.00
M36	2	Fine	34.701	33.835	33.546	34.00
M36	1.5	Fine	35.026	34.376	34.160	34.50
M38	1.5	Coarse	37.026	36.376	36.160	36.50
M39	4	Coarse	36.402	34.670	34.093	35.00
M39	3	Fine	37.051	35.752	35.319	36.00
M39	2	Fine	37.701	36.835	36.546	37.00
M39	1.5	Fine	38.026	37.376	37.160	37.50
M40	3	Coarse	38.051	36.752	36.319	37.00
M40	2	Fine	38.701	37.835	37.546	38.00
M40	1.5	Fine	39.026	38.376	38.160	38.50
M42	4.5	Coarse	39.077	37.129	36.479	37.50
M42	4	Fine	39.402	37.670	37.093	38.00
M42	3	Fine	40.051	38.752	38.319	39.00
M42	2	Fine	40.701	39.835	39.546	40.00
M42	1.5	Fine	41.026	40.376	40.160	40.50
M45	4.5	Coarse	42.077	40.129	39.479	40.50
M45	4	Fine	42.402	40.670	40.093	41.00
M45	3	Fine	43.051	41.752	41.319	42.00
M45	2	Fine	43.701	42.835	42.546	43.00
M45	1.5	Fine	44.026	43.376	43.160	43.50
M48	5	Coarse	44.752	42.587	41.866	43.00
M48	4	Fine	45.402	43.670	43.093	44.00
M48	3	Fine	46.051	44.752	44.319	45.00
M48	2	Fine	46.701	45.835	45.546	46.00
M48	1.5	Fine	47.026	46.376	46.160	46.50
M50	3	Coarse	48.051	46.752	46.319	47.00
M50	2	Fine	48.701	47.835	47.546	48.00
M50	1.5	Fine	49.026	48.376	48.160	48.50
M52	5	Coarse	48.752	46.587	45.866	47.00
M52	4	Fine	49.402	47.670	47.093	48.00
M52	3	Fine	50.051	48.752	48.319	49.00
M52	2	Fine	50.701	49.835	49.546	50.00
M52	1.5	Fine	51.026	50.376	50.160	50.50
M55	4	Coarse	52.402	50.670	50.093	51.00
M55	3	Fine	53.051	51.752	51.319	52.00
M55	2	Fine	53.701	52.835	52.546	53.00
M55	1.5	Fine	54.026	53.376	53.160	53.50
M56	5.5	Coarse	52.428	50.046	49.252	50.50
M56	5	Fine	52.752	50.587	49.866	51.00
M56	4	Fine	53.402	51.670	51.093	52.00
M56	3	Fine	54.051	52.752	52.319	53.00
M56	2	Fine	54.701	53.835	53.546	54.00
M56	1.5	Fine	55.026	54.376	54.160	54.50
M58	4	Coarse	55.402	53.670	53.093	54.00
M58	3	Fine	56.051	54.752	54.319	55.00
M58	2	Fine	56.701	55.835	55.546	56.00
M58	1.5	Fine	57.026	56.376	56.160	56.50
M60	5.5	Coarse	56.428	54.046	53.252	54.50
M60	4	Fine	57.402	55.670	55.093	56.00
M60	3	Fine	58.051	56.752	56.319	57.00
M60	2	Fine	58.701	57.835	57.546	58.00
M60	1.5	Fine	59.026	58.376	58.160	58.50
M62	4	Coarse	59.402	57.670	57.093	58.00
M62	3	Fine	60.051	58.752	58.319	59.00
M62	2	Fine	60.701	59.835	59.546	60.00
M62	1.5	Fine	61.026	60.376	60.160	60.50
M64	6	Coarse	60.103	57.505	56.639	58.00
M64	4	Fine	61.402	59.670	59.093	60.00
M64	3	Fine	62.051	60.752	60.319	61.00
M64	2	Fine	62.701	61.835	61.546	62.00
M64	1.5	Fine	63.026	62.376	62.160	62.50
M65	4	Coarse	62.402	60.670	60.093	61.00
M65	3	Fine	63.051	61.752	61.319	62.00
M65	2	Fine	63.701	62.835	62.546	63.00
M65	1.5	Fine	64.026	63.376	63.160	63.50
M68	6	Coarse	64.103	61.505	60.639	62.00
M68	4	Fine	65.402	63.670	63.093	64.00
M68	3	Fine	66.051	64.752	64.319	65.00
M68	2	Fine	66.701	65.835	65.546	66.00
M68	1.5	Fine	67.026	66.376	66.160	66.50
M70	6	Coarse	66.103	63.505	62.639	64.00
M70	4	Fine	67.402	65.670	65.093	66.00
M70	3	Fine	68.051	66.752	66.319	67.00
M70	2	Fine	68.701	67.835	67.546	68.00
M70	1.5	Fine	69.026	68.376	68.160	68.50
M72	6	Coarse	68.103	65.505	64.639	66.00
M72	4	Fine	69.402	67.670	67.093	68.00
M72	3	Fine	70.051	68.752	68.319	69.00
M72	2	Fine	70.701	69.835	69.546	70.00
M72	1.5	Fine	71.026	70.376	70.160	70.50
M75	4	Coarse	72.402	70.670	70.093	71.00
M75	3	Fine	73.051	71.752	71.319	72.00
M75	2	Fine	73.701	72.835	72.546	73.00
M75	1.5	Fine	74.026	73.376	73.160	73.50
M76	6	Coarse	72.103	69.505	68.639	70.00
M76	4	Fine	73.402	71.670	71.093	72.00
M76	3	Fine	74.051	72.752	72.319	73.00
M76	2	Fine	74.701	73.835	73.546	74.00
M76	1.5	Fine	75.026	74.376	74.160	74.50
M78	2	Coarse	76.701	75.835	75.546	76.00
M80	6	Coarse	76.103	73.505	72.639	74.00
M80	4	Fine	77.402	75.670	75.093	76.00
M80	3	Fine	78.051	76.752	76.319	77.00
M80	2	Fine	78.701	77.835	77.546	78.00
M80	1.5	Fine	79.026	78.376	78.160	78.50
M82	2	Coarse	80.701	79.835	79.546	80.00
M85	6	Coarse	81.103	78.505	77.639	79.00
M85	4	Fine	82.402	80.670	80.093	81.00
M85	3	Fine	83.051	81.752	81.319	82.00
M85	2	Fine	83.701	82.835	82.546	83.00
M90	6	Coarse	86.103	83.505	82.639	84.00
M90	4	Fine	87.402	85.670	85.093	86.00
M90	3	Fine	88.051	86.752	86.319	87.00
M90	2	Fine	88.701	87.835	87.546	88.00
M95	6	Coarse	91.103	88.505	87.639	89.00
M95	4	Fine	92.402	90.670	90.093	91.00
M95	3	Fine	93.051	91.752	91.319	92.00
M95	2	Fine	93.701	92.835	92.546	93.00
M100	6	Coarse	96.103	93.505	92.639	94.00
M100	4	Fine	97.402	95.670	95.093	96.00
M100	3	Fine	98.051	96.752	96.319	97.00
M100	2	Fine	98.701	97.835	97.546	98.00
M105	6	Coarse	101.103	98.505	97.639	99.00
M105	4	Fine	102.402	100.670	100.093	101.00
M105	3	Fine	103.051	101.752	101.319	102.00
M105	2	Fine	103.701	102.835	102.546	103.00
M110	6	Coarse	106.103	103.505	102.639	104.00
M110	4	Fine	107.402	105.670	105.093	106.00
M110	3	Fine	108.051	106.752	106.319	107.00
M110	2	Fine	108.701	107.835	107.546	108.00
M115	6	Coarse	111.103	108.505	107.639	109.00
M115	4	Fine	112.402	110.670	110.093	111.00
M115	3	Fine	113.051	111.752	111.319	112.00
M115	2	Fine	113.701	112.835	112.546	113.00
M120	6	Coarse	116.103	113.505	112.639	114.00
M120	4	Fine	117.402	115.670	115.093	116.00
M120	3	Fine	118.051	116.752	116.319	117.00
M120	2	Fine	118.701	117.835	117.546	118.00
M125	8	Coarse	119.804	116.340	115.185	117.00
M125	6	Fine	121.103	118.505	117.639	119.00
M125	4	Fine	122.402	120.670	120.093	121.00
M125	3	Fine	123.051	121.752	121.319	122.00
M125	2	Fine	123.701	122.835	122.546	123.00
M130	8	Coarse	124.804	121.340	120.185	122.00
M130	6	Fine	126.103	123.505	122.639	124.00
M130	4	Fine	127.402	125.670	125.093	126.00
M130	3	Fine	128.051	126.752	126.319	127.00
M130	2	Fine	128.701	127.835	127.546	128.00
M135	6	Coarse	131.103	128.505	127.639	129.00
M135	4	Fine	132.402	130.670	130.093	131.00
M135	3	Fine	133.051	131.752	131.319	132.00
M135	2	Fine	133.701	132.835	132.546	133.00
M140	8	Coarse	134.804	131.340	130.185	132.00
M140	6	Fine	136.103	133.505	132.639	134.00
M140	4	Fine	137.402	135.670	135.093	136.00
M140	3	Fine	138.051	136.752	136.319	137.00
M140	2	Fine	138.701	137.835	137.546	138.00
M145	6	Coarse	141.103	138.505	137.639	139.00
M145	4	Fine	142.402	140.670	140.093	141.00
M145	3	Fine	143.051	141.752	141.319	142.00
M145	2	Fine	143.701	142.835	142.546	143.00
M150	8	Coarse	144.804	141.340	140.185	142.00
M150	6	Fine	146.103	143.505	142.639	144.00
M150	4	Fine	147.402	145.670	145.093	146.00
M150	3	Fine	148.051	146.752	146.319	147.00
M150	2	Fine	148.701	147.835	147.546	148.00
M155	6	Coarse	151.103	148.505	147.639	149.00
M155	4	Fine	152.402	150.670	150.093	151.00
M155	3	Fine	153.051	151.752	151.319	152.00
M160	8	Coarse	154.804	151.340	150.185	152.00
M160	6	Fine	156.103	153.505	152.639	154.00
M160	4	Fine	157.402	155.670	155.093	156.00
M160	3	Fine	158.051	156.752	156.319	157.00
M165	6	Coarse	161.103	158.505	157.639	159.00
M165	4	Fine	162.402	160.670	160.093	161.00
M165	3	Fine	163.051	161.752	161.319	162.00
M170	8	Coarse	164.804	161.340	160.185	162.00
M170	6	Fine	166.103	163.505	162.639	164.00
M170	4	Fine	167.402	165.670	165.093	166.00
M170	3	Fine	168.051	166.752	166.319	167.00
M175	6	Coarse	171.103	168.505	167.639	169.00
M175	4	Fine	172.402	170.670	170.093	171.00
M175	3	Fine	173.051	171.752	171.319	172.00
M180	8	Coarse	174.804	171.340	170.185	172.00
M180	6	Fine	176.103	173.505	172.639	174.00
M180	4	Fine	177.402	175.670	175.093	176.00
M180	3	Fine	178.051	176.752	176.319	177.00
M185	6	Coarse	181.103	178.505	177.639	179.00
M185	4	Fine	182.402	180.670	180.093	181.00
M185	3	Fine	183.051	181.752	181.319	182.00
M190	8	Coarse	184.804	181.340	180.185	182.00
M190	6	Fine	186.103	183.505	182.639	184.00
M190	4	Fine	187.402	185.670	185.093	186.00
M190	3	Fine	188.051	186.752	186.319	187.00
M195	6	Coarse	191.103	188.505	187.639	189.00
M195	4	Fine	192.402	190.670	190.093	191.00
M195	3	Fine	193.051	191.752	191.319	192.00
M200	8	Coarse	194.804	191.340	190.185	192.00
M200	6	Fine	196.103	193.505	192.639	194.00
M200	4	Fine	197.402	195.670	195.093	196.00
M200	3	Fine	198.051	196.752	196.319	197.00
M205	6	Coarse	201.103	198.505	197.639	199.00
M205	4	Fine	202.402	200.670	200.093	201.00
M205	3	Fine	203.051	201.752	201.319	202.00
M210	8	Coarse	204.804	201.340	200.185	202.00
M210	6	Fine	206.103	203.505	202.639	204.00
M210	4	Fine	207.402	205.670	205.093	206.00
M210	3	Fine	208.051	206.752	206.319	207.00
M215	6	Coarse	211.103	208.505	207.639	209.00
M215	4	Fine	212.402	210.670	210.093	211.00
M215	3	Fine	213.051	211.752	211.319	212.00
M220	8	Coarse	214.804	211.340	210.185	212.00
M220	6	Fine	216.103	213.505	212.639	214.00
M220	4	Fine	217.402	215.670	215.093	216.00
M220	3	Fine	218.051	216.752	216.319	217.00
M225	6	Coarse	221.103	218.505	217.639	219.00
M225	4	Fine	222.402	220.670	220.093	221.00
M225	3	Fine	223.051	221.752	221.319	222.00
M230	8	Coarse	224.804	221.340	220.185	222.00
M230	6	Fine	226.103	223.505	222.639	224.00
M230	4	Fine	227.402	225.670	225.093	226.00
M230	3	Fine	228.051	226.752	226.319	227.00
M235	6	Coarse	231.103	228.505	227.639	229.00
M235	4	Fine	232.402	230.670	230.093	231.00
M235	3	Fine	233.051	231.752	231.319	232.00
M240	8	Coarse	234.804	231.340	230.185	232.00
M240	6	Fine	236.103	233.505	232.639	234.00
M240	4	Fine	237.402	235.670	235.093	236.00
M240	3	Fine	238.051	236.752	236.319	237.00
M245	6	Coarse	241.103	238.505	237.639	239.00
M245	4	Fine	242.402	240.670	240.093	241.00
M245	3	Fine	243.051	241.752	241.319	242.00
M250	8	Coarse	244.804	241.340	240.185	242.00
M250	6	Fine	246.103	243.505	242.639	244.00
M250	4	Fine	247.402	245.670	245.093	246.00
M250	3	Fine	248.051	246.752	246.319	247.00
M255	6	Coarse	251.103	248.505	247.639	249.00
M255	4	Fine	252.402	250.670	250.093	251.00
M260	8	Coarse	254.804	251.340	250.185	252.00
M260	6	Fine	256.103	253.505	252.639	254.00
M260	4	Fine	257.402	255.670	255.093	256.00
M265	6	Coarse	261.103	258.505	257.639	259.00
M265	4	Fine	262.402	260.670	260.093	261.00
M270	8	Coarse	264.804	261.340	260.185	262.00
M270	6	Fine	266.103	263.505	262.639	264.00
M270	4	Fine	267.402	265.670	265.093	266.00
M275	6	Coarse	271.103	268.505	267.639	269.00
M275	4	Fine	272.402	270.670	270.093	271.00
M280	8	Coarse	274.804	271.340	270.185	272.00
M280	6	Fine	276.103	273.505	272.639	274.00
M280	4	Fine	277.402	275.670	275.093	276.00
M285	6	Coarse	281.103	278.505	277.639	279.00
M285	4	Fine	282.402	280.670	280.093	281.00
M290	8	Coarse	284.804	281.340	280.185	282.00
M290	6	Fine	286.103	283.505	282.639	284.00
M290	4	Fine	287.402	285.670	285.093	286.00
M295	6	Coarse	291.103	288.505	287.639	289.00
M295	4	Fine	292.402	290.670	290.093	291.00
M300	8	Coarse	294.804	291.340	290.185	292.00
M300	6	Fine	296.103	293.505	292.639	294.00
M300	4	Fine	297.402	295.670	295.093	296.00

Disclaimer

Tap drill sizes and practical notes are provided as general guidance based on engineering practice and are not part of the ISO 724:2023 standard. For critical applications, consult relevant standards (ISO 261:1998 for coarse/fine pitch definitions, ISO 965-1 for tolerances, ISO 2306 for tap drill sizes) or manufacturer specifications. The formulas D₂, d₂, D₁, and d₃ are from ISO 724:2023.

Reference: ISO 724:2023 – ISO General Purpose Metric Screw Threads – Basic Dimensions

METRIC THREAD DESIGNATION – QUICK GUIDE FOR DRAWINGS

COMPLETE METRIC THREAD SIZE TABLE AND SELECTION MANUAL

STANDARD METRIC THREAD SIZE TABLE

ISO 965-1

MODULUS METAL
Sand Casting in Turkey, Permanent Mold Casting in Turkey, Gravity Die Casting in Turkey, Pressure Die Casting in Turkey, High-Pressure Die Casting in Turkey, Investment Casting in Turkey, Foundry in Turkey, Plastic Injection Molding in Turkey, Press Bending ( Press Brake) Products in Turkey, Laser and Plasma Cutting in Turkey, Welded Construction in Turkey, Heat Treatment, CNC Machined Products Manufacturer in Turkey, Additive Manufacturing and 3D Printing in Turkey, Quality Enginering and Inspection Service in Turkey, Manufacturing Inspection Service in Turkey, Quality Engineering and Supplier Quality Engineering Service in Turkey, Supplier Quality Control and Inspection Service in Turkey, Resident Engineering Services in Turkey