hydraulic nuts

The Hydraulic Nut is a permanent fixture, replacing the conventional nut and retaining the high bolt load and extension in small space envelopes where there may not be sufficient space to use tensioners. The nut can be retrofitted to existing plant and is a simple and accurate solution to mechanical jointing problems.

The locking for hydraulic nuts is different from common nuts. When the hydraulic nut is locking, it causes ultra-high pre-tightening force by hydraulic pressure (about 200 MPa), which can get close to the yield point of the bolts. It will not loosen even if it is in vibrating condition.

Hydraulic nut is especially suitable in the fastening for the coal miners and roadheaders in underground mining where the space is very narrow. It can also be used in the machines for metallurgy , chemical industry and engineering machinery.

Working principle of hydraulic nuts :

Hydraulic nut is a kind of locking device which relies on pre-tightening force that can make the connecting nuts longer. So the high-strength two head nuts above 10.9 grade must be used.

No. Code name M Model Overall dimensionsΦB×A Route
1 KMYE M24×2 Φ62×50 5
2 FMYE M24×3(Reverse installation) Φ62×52 5
3 KMYGA M27×3 Φ68×50 5.5
4 KMYGB M27×2 Φ68×50 5.5
5 KMYA M30×3.5 Φ68×50 5.5
6 KMYB M30×3 Φ68×50 5.5
7 KMYBI M30×2 Φ68×50 5.5
8 KMYH M33×3.5 Φ82.5×64.5 5.5
9 KMYD M36×3 Φ82.5×64.5 14
10 KMYF M42×3 Φ84×61 10
11 KMYC M42×3(Major external diameter) Φ94×66 14
12 KMYI M48×3 Φ106×67.5 14
13 KMYJ M52×3 Φ106×67.5 14
14 KMYK M64×4 Φ125×82 14
15 KMYR M95×2 Φ195×132.5 14
16 FMYQ M110×2 Φ215×153 14
17 KMYA M30×3.5(Reverse installation) Φ68×49.2 14
18 KMYKA M56×4 Φ125×82 14
19 FMYK M64×4 Φ125×110 14