DIN 6912 – Hex Socket Low Cap Head Screw With Pilot Hole

DIN 6912 specifies the requirements for hexagon socket head cap screws with a low head and a specialized pilot hole. These fasteners are engineered for applications where vertical clearance is limited, but high-precision engagement is required. Unlike standard socket screws, DIN 6912 features a distinct center hole within the hexagonal drive. While it shares a similar low-profile geometry with DIN 7984, the inclusion of the pilot recess allows for specialized tooling and ensures the fastener can be utilized in security or high-vibration environments where drive stability is paramount.

DIN 6912 Hexagon Socket Low Cap Screw Schematic

DIN 6912 - Dimensions
Thread Size		M4	M5	M6	M8	M10	M12	M14	M16	M18	M20	M22	M24	M27	M30	M33	M36
dk	Max	7	8.5	10	13	16	18	21	24	27	30	33	36	40	45	50	54
dk	Min	6.78	8.28	9.78	12.73	15.73	17.73	20.67	23.67	26.67	29.67	32.61	65.61	39.61	44.61	49.61	53.54
k	Max	2.8	3.5	4	5	6.5	7.5	8.5	10	11	12	13	14	16	17.5	19.5	21.5
k	Min	2.66	3.32	3.82	4.82	6.28	7.28	8.28	9.78	10.73	11.73	12.73	13.73	15.73	17.23	19.17	21.17
t1	Nom	1.6	2	2.5	3	3.5	4	4.5	5.5	6	6.5	7	7	8.5	9	10	11.5
	Max	1.72	2.12	2.62	3.12	3.65	4.15	4.65	5.65	6.15	6.68	7.18	7.18	8.68	9.18	10.18	11.72
	Min	1.48	1.88	2.38	2.88	3.35	3.85	4.35	5.35	5.85	6.32	6.82	6.82	8.32	8.82	9.82	11.28
t2	Max	3.6	4.3	5.3	6.86	7.86	9.36	10.36	11.93	12.93	14.43	15.43	16.43	17.43	19.52	20.52	24.52
t2	Min	3.3	4	5	6.5	7.5	9	10	11.5	12.5	14	15	16	17	19	20	24
dh	Max	2.06	2.56	3.06	4.075	5.075	6.075	7.09	8.09	8.09	10.09	10.09	12.11	12.11	15.11	16.61	18.11
dh	Min	2	2.5	3	4	5	6	7	8	8	10	10	12	12	15	16.5	18
s	Nom	3	4	5	6	8	10	12	14	14	17	17	19	19	22	24	27
	Max	3.1	4.12	5.14	6.14	8.175	10.175	12.212	14.212	14.212	17.23	17.23	19.275	19.275	22.275	24.275	27.275
	Min	3.02	4.02	5.02	6.02	8.025	10.025	12.032	14.032	14.032	17.05	17.05	19.065	19.065	22.065	24.065	27.065
e	Min	3.44	4.58	5.72	6.86	9.15	11.43	13.72	16	16	19.44	19.44	21.73	21.73	25.15	27.43	30.85
v	Max	0.4	0.5	0.6	0.8	1	1.2	1.4	1.6	1.8	2	2.2	2.4	2.7	3	3.3	3.6
r	Min	0.2	0.2	0.25	0.4	0.4	0.6	0.6	0.6	0.6	0.8	0.8	0.8	1	1	1	1
lf	Max	0.6	0.6	0.68	1.02	1.02	1.45	1.45	1.45	1.87	2.04	2.04	2.04	2.89	2.89	2.89	2.89
dw	Min	6.2	7.7	9.2	12.03	15.03	17.03	19.83	22.83	25.83	28.83	31.61	34.61	38.61	43.61	48.61	52.34
da	Max	4.7	5.7	6.8	9.2	11.2	13.7	15.7	17.7	20.2	22.4	24.4	26.4	30.4	33.4	36.4	39.4
ds	Max	4	5	6	8	10	12	14	16	18	20	22	24	27	30	33	36
ds	Min	3.82	4.82	5.82	7.78	9.78	11.73	13.73	15.73	17.73	19.67	21.67	23.67	26.67	29.67	32.61	65.61
b (Ref)	l ≤ 125	14	16	18	22	26	30	34	38	42	46	50	54	60	66	72	78
	l ≤ 200	—	—	—	—	32	36	40	44	48	52	56	60	66	72	78	84
	l > 200	—	—	—	—	—	—	—	57	61	65	69	73	79	85	91	97

Note: All measurement are in mm

Disclaimer: The dimensions presented on this page are based on the applicable industry standard. However, actual product measurements may vary slightly due to manufacturing practices, material selection, surface finish, and specified tolerance classes. Buyers and sourcing professionals are encouraged to verify final specifications with the manufacturer or supplier prior to procurement, particularly for critical applications.

Legend

dk – Head diameter.
da – Transition diameter (max).
ds – Shank diameter.
k – Head height.
s – Width across flats of the internal hexagon socket. determining the required allen keys
t1 – Total depth of the internal hexagon socket.
t2 – Depth of the pilot hole (nominal/min/max).
e – Width across corners of the internal hexagon socket (min).
dw – Minimum bearing diameter under the head.
b – Reference thread length (dependent on screw length ).
r – Radius of the underhead fillet (min).
dh – Diameter of the pilot hole.
v – Maximum underhead fillet depth/curvature.
lf – Thread run-out (max).
Ref (Reference value) – A theoretical dimension provided for information and design guidance only. Reference values (like b) are not requirements for inspection but assist in geometry calculation.

Technical Note

lg max – The maximum length of the unthreaded portion, calculated as nominal length (l) - reference thread length (b).
The minimum value of ls (unthreaded shank length) can be determined by:
ls min = lg max − 5P
where P is the thread pitch.
Pilot Hole – Unlike low-cap head screws under DIN 7984, DIN 6912 screws feature a pilot hole (dh) within the socket, which is reflected in the (t1) and (t2) dimensions.
Standard nominal lengths (l) under DIN 6912 are generally available in the following ranges:
- For sizes M4 – M16: 10 mm to 140 mm
- For sizes M18 – M36: 20 mm to 200 mm

Standard Body Lengths and Tolerances
Nominal Length (l)	Min (mm)	Max (mm)
10 mm	9.71	10.29
12 mm	11.65	12.35
16 mm	15.65	16.35
20 mm	19.58	20.42
25 mm	24.58	25.42
30 mm	29.58	30.42
35 mm	34.5	35.5
40 mm	39.5	40.5
50 mm	49.5	50.5
60 mm	59.4	60.6
70 mm	69.4	70.6
80 mm	79.4	80.6
90 mm	89.3	90.7
100 mm	99.3	100.7
110 mm	109.3	110.7
120 mm	119.3	120.7
130 mm	129.2	130.8
140 mm	139.2	140.8
150 mm	149.2	150.8
160 mm	159.2	160.8
170 mm	169.2	170.8
180 mm	179.2	180.8
190 mm	189.1	190.9
200 mm	199.1	200.9

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