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    Perth

    Brisbane / PNG

    Torque Tightening

    AUSTRALIAN

    OWNED AND OPERATED

    What is Torque?

    It is a measure of how much force acting on an object which causes that object to rotate.

    What is Torque Tightening?

    The application of preload to a fastener by the turning of the fastener’s nut.

    Torque Tightening and Preload

    The amount of preload created when torquing is largely dependant on the effects of friction.

    Principally there are three different “torque components”:

    • torque to stretch the bolt
    • torque to overcome friction in bolt and nut threads
    • torque to overcome friction at the nut spot face (bearing contact surface)

    * Preload (residual load) = Applied Torque minus Frictional Losses *

    Friction points should always be lubricated when using the torque tightening method.

    Example of how a lubricant can reduce the effect of friction and convert more torque to bolt preload.

    Lubrication Reduces Friction

    Lubrication reduces the friction during tightening, decreases bolt failure during installation and increases bolt service life. Variation in friction coefficients affect the amount of preload achieved at a specified torque. Higher friction results in less conversion of torque to preload. The value for the friction coefficient provided by the lubricant manufacturer must be known to accurately establish the required torque value.

    Lubricant or anti-seizure compounds should be applied to both the nut bearing surface and the male threads.

    Torque Procedure

    When torquing it is common to tighten only one bolt at a time, this can result in Point Loading and Load Scatter. To avoid this, torque is applied in stages following a prescribed pattern:

    Step 1: Spanner tight ensuring that 2-3 threads extend above nut

    Step 2: Tighten each bolt to one-third of the final required torque following the pattern as shown above.

    Step 3: Increase the torque to two-thirds following the pattern shown above.

    Step 4: Increase the torque to full torque following the pattern shown above.

    Step 5: Perform one final pass on each bolt working clockwise from bolt 1, at the full final torque.

    Breakout Torque

    When loosening bolts a torque value higher than the tightening torque is normally required. This is mainly due to corrosion and deformations in the bolt and nut threads.

    Breakout torque cannot be accurately calculated, however, depending on conditions it can take up to 2 1/2 times the input torque to breakout.

    The use of penetrating oils or anti-seize products is always recommended when performing breakout operations.

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    Jutta TilleryJutta Tillery
    14:34 02 Apr 22
    Excellent customer service, kept us updated throughout the delivery process really looking forward to doing business with Waltan Tools again soon
    Daniel and ScottDaniel and Scott
    12:02 29 Jun 21
    We have done business with Winnellie Hydraulics on numerous occasions and find them to always be nothing but professional, honest and reliable.Their customer service is excellent and they are always a pleasure to work with. We would highly recommend Winnellie Hydraulics and we look forward to continuing business with Max and the team in the up and coming future.
    Damien PedersenDamien Pedersen
    06:23 15 Feb 21
    Winnellie Hydraulics are up most professional and I am always impressed with the service offered and provided. The team at Winnellie Hydraulics are highly skilled, innovative and ever reliable. They continue to be the Territory’s leading service specialists within the fields of the hydraulic and pneumatic services and solutions. The team have a broad range of knowledge in hydraulic, pneumatic, hose management and products across a extensive range of divisions. The team at Winnellie Hydraulics are easy to work with and really appreciate their customers and strive for continuous business improvement.
    Rob NorthRob North
    07:53 10 Feb 21
    Efficient, professional and dedicated. The team at Winnellie Hydraulics are a pleasure to work with and are customer service specialists.Max and the team have taken on many challenges to assist with emergent scopes at our onshore facility in Darwin. They go above and beyond to meet the timeline required without missing a beat on quality.I highly recommend dealing with them and look forward to future business.Thanks guys
    Sonia HarveySonia Harvey
    05:25 08 Feb 21
    The team at Winnellie Hydraulics are customer service specialists! They certainly go above and beyond to meet the needs of customers and are a great local service and supply business. I highly recommend dealing with them.
    Darren SteeleDarren Steele
    02:59 07 Feb 21
    For all your Hydraulic & Pneumatic needs, Winnellie Hydraulics has you covered.Max and the team run a great operation that supports the Oil & Gas and Mining industries.With great brands supporting them, they are truly the one stop shop for all your engineering needs.
    Dipak NandDipak Nand
    23:06 04 Feb 21
    The team at Winnellie hydraulics, is great to work with, they understand our priority and service delivery to our Defence clients, No job too small or big and delivering of high quality products and service. Also really easy to deal with in regards to faults/ warranty and SME service . Highly recommended to use.
    Ben TilbrookBen Tilbrook
    07:35 04 Feb 21
    Outstanding commitment to their customers, in my experience there isn’t anything that is too hard for this mob. Always prepared to find solutions to their customers now matter how big or small the request. A great family business who take pride in providing product and service.
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