Ferry Bolts 12 Points

To avoid the long delivery time of M20 and above large-diameter bolts, Xiaoguo® Ferry Bolts 12 points is equipped with regular stocks of M22, M24, M27, and M30. The longest length reaches up to 200mm. If customers urgently need them, we can deliver within 48 hours, reducing the waiting time.

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Product Description

Proper usage

To extend the service life of the Ferry Bolts 12 points, proper usage can effectively prevent some losses of the products. Please read the following content and use the products in accordance with the norms.

（1）Preparation of threaded holes

Clean the threads: Before installation, remove oil stains, iron filings, old thread glue, rust, etc. from the thread holes.

Corner rounding of the orifice: Ensure that the flange surface of the Ferry Bolts 12 points can be perfectly aligned with the workpiece plane, avoiding any gaps.

Thread hole depth: For steel parts, the engagement depth should be at least 1 times the thread diameter; for soft materials such as cast iron and aluminum alloys, it should be at least 1.5 to 2 times the diameter.

（2）Use the correct tools

It is necessary to use a 12-point socket or a 12-point star wrench. It is strictly prohibited to use hexagonal sockets or open-end wrenches.

Ensure that the size of the socket matches precisely with the dimension of the opposite edge of the bolt head (for example, for M10, use a 12mm 12-point socket).

（3）Use a torque wrench to tighten step by step

Tighten according to the standard recommended torque value (refer to the 12.9 grade dry thread reference torque):

Specification	Recommended Torque (N·m)	Specification	Recommended Torque (N·m)
M6	12-15	5/16″	20-25
M8	28-32	3/8″	40-45
M10	55-65	7/16″	60-70
M12	95-110	1/2″	100-120
M14	150-170	9/16″	140-160
M16	230-260	5/8″	190-220

（4）Use washers (if necessary)

The Ferry Bolts 12 points comes with a flange surface and usually does not require a washer. However, if the installation surface is not flat, a steel flat washer can be added to ensure that the flange surface is fully in contact. (The thickness of the washer must not exceed 1mm.)

（5）Anti-biting treatment (made of stainless steel)

The stainless steel material is prone to Galling when tightened at high speed or with high torque. Before installation, a anti-adhesion agent must be applied to the threads.

Ferry Bolts 12 Points

Special material storage requirements

For the special material Ferry Bolts 12 points, we have also summarized the following information, hoping to be of assistance to you.

（1）Stainless steel: Do not mix with carbon steel products. The storage area should be kept clean and free of iron filings.

（2）Titanium alloy: Avoid contact with chlorine, fluorine and other halogens; do not come into direct contact with stainless steel to prevent electrochemical corrosion.

（3）Aluminum alloy: Avoid contact with strong acids and strong alkalis; the surface anodized products need to be protected from scratches.

（4）Brass: Avoid contact with ammonia gas (which is prone to cause stress corrosion cracking).

Ferry Bolts 12 Points

Mon	M22	M24	M27	M30	M33	M36	M39	M42	M45	M48	M52
P	2.5	3	3	3.5	3.5	4	4	4.5	4.5	5	5
dc max	33.3	38.1	38.1	42.8	47.5	52.3	57	61.7	66.5	76	76
dc min	32.68	37.48	37.48	42.18	46.88	51.56	56.26	60.96	65.76	75.26	75.26
ds max	22	24	27	30	33.0	36	39	42.0	45.0	48	52
ds min	21.79	23.79	26.79	29.79	32.75	35.75	38.75	41.75	44.75	47.75	51.7
e min	25.4	27.7	27.7	34.6	36.90	41.60	47.30	47.30	53.10	57.70	57.70
h max	6.9	7.98	7.98	9.21	9.62	10.82	12.71	12.56	15.65	16.1	16.1
h min	6.54	7.35	7.35	8.78	9.19	10.39	12.28	12.13	15.13	15.58	15.58
k max	22.36	25.56	25.56	28.96	32.0	35.2	38.3	41.4	44.7	51.03	51.03
k min	22.04	25.24	25.24	28.54	31.6	34.80	37.90	41.00	44.30	50.57	50.57
r max	1	1.2	1.20	1.4	1.60	1.60	1.80	1.80	2.00	2.20	2.20
r min	0.75	0.95	0.95	1.15	1.35	1.35	1.55	1.55	1.75	1.82	1.82
s max	22	24	24	30	32.00	36.00	41.00	41.00	46.0	50.0	50.0
s min	21.79	23.79	23.79	29.79	31.75	35.75	40.75	40.75	45.75	49.75	49.75