IS 12427

TRANSMISSION TOWER BOLTS

IS 12427 : 2001

Steel Hardness: 5.8 , 8.8
Finish: Hot Dip Galvanized

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Dimensions / Weight Chart

Dimensions of Hexagon Head Transmission Tower Bolts
Nom. Dia. (d)	M12	M16	M20	(M22)	M24
Thread Pitch	1.75	2	2.5	2.5	3
b (ref)	20	23	26	28	30
C	Max.	0.6	0.8	0.8	0.8	0.8
Da	Max.	14.7	18.7	24.4	26.4	28.4
Ds	Max.	12.7	16.7	20.84	22.84	24.84
Min.	11.3	15.3	19.16	21.16	23.16
Dw	Max.	18	24	30	34	36
Min.	16.47	22	27.7	31.35	33.25
e	Min.	19.85	26.17	32.95	37.29	39.55
k	Nom.	7.5	10	12.5	14	15
Max.	7.95	10.75	13.4	14.9	15.9
Min.	7.05	9.25	11.6	13.1	14.1
k’	Min.	4.95	6.48	8.12	9.17	9.87
r	Min.	0.6	0.6	0.8	0.8	0.8
s	Max.	18	24	30	34	36
Min.	17.57	23.16	29.16	33	35

Length — Size Combinations and Grip Ranges
Thread	M12	M16	M20	M22	M24
Size d	ls	Lg	Grip	ls	Lg	Grip	ls	Lg	Grip	ls	Lg	Grip	ls	Lg	Grip
Min.	Max.	Range	Min.	Max.	Range	Min.	Max.	Range	Min.	Max.	Range	Min.	Max.	Range
30	65	10	6-10	–	–	–	–	–	–	–	–	–	–	–	–
35	11.5	15	11-15	8	12	8-12	–	–	–	–	–	–	–	–	–
40	16.5	20	16-20	13	17	13-17	9	14	11-14	7	12	8-12	–	–	–
45	21.5	25	21-25	18	22	18-22	14	19	15-19	12	17	13-17	9	15	11-15
50	26.5	30	26-30	23	27	23-27	19	24	20-24	17	22	18-22	14	20	16-20
55	31.5	35	31-35	28	32	28-32	24	29	25-29	22	27	23-27	19	25	21-25
60	36.5	40	36-40	33	37	33-37	29	34	30-34	27	32	28-32	24	30	36-30
65	41.5	45	41-45	38	42	38-42	34	39	35-39	32	37	33-37	29	35	31-35
70	46.5	50	46-50	43	47	43-47	39	44	40-44	37	42	38-42	34	40	36-40
75	51.5	55	51-55	48	52	48-52	44	49	45-49	42	47	43-47	39	45	41-45
80	56,5	60	56-60	53	57	53-57	49	54	50-54	47	52	48-52	44	50	46-50
85	61.5	65	61-65	58	62	58-62	54	59	55-59	52	57	53-57	49	55	51-55
90	66.5	70	66-70	63	67	63-67	59	64	60-64	57	62	58-62	54	60	56-60
95	71.5	75	71-75	68	72	68-72	64	69	65-69	62	67	63-67	59	65	61-65
100	76.5	80	76-80	73	77	73-77	69	74	70-74	67	72	68-72	64	70	66-70
105				78	82	78-82	74	79	75-79	72	77	73-77	69	75	71-75
110				83	87	83-87	79	84	80-84	77	82	78-82	74	80	76-80
115				88	92	88-92	84	89	85-89	82	87	83-87	79	85	81-85
120				93	97	93-97	89	94	90-94	87	92	88-92	84	90	86-90
125				98	102	98-102	94	99	95-99	92	97	93-97	89	95	91-95
130				103	107	103-107	99	104	100-104	97	102	98-102	94	100	96- I00
135				108	112	108-112	104	109	105-109	102	107	103-107	99	105	101-105
140				113	117	113-117	109	114	110-114	107	112	108-112	I04	110	106-110
145				118	122	118-122	114	119	115-119	112	117	113-117	109	115	111-115
150				123	127	123-127	119	124	120-124	117	I22	118-122	114	120	116-120
155				I28	132	128-132	124	129	125-129	122	I27	123-127	119	125	121-125
160				133	137	133-137	129	I34	130-134	127	132	128-132	124	130	126-130