Civil4M

Civil4M

What is rolling margin in reinforcement steel?

What is rolling margin in reinforcement steel

Hi all civil engineers when we receive a new lot of steel we need to check it for rolling margin and other required quick tests for acceptance of steel which are as follows:


1) You should check for rusting of steel, slitely rusted steel is good for bonding. the steel should not show a scaling effect over it.
2) if it shows scaling and the ribs of steel are not seen due to rusting then this type of steel should not be accepted in any condition.
3) you need to take a sample bars from differant bundles approx length of 1 meter.
4) check at least 3 bars for its unit weight.
5) when you compare the actual weight vs therotical weight and calculate the weight of steel theoratically it is called as rolling margine.
6) if steel is overweight then you definately gonna get less steel qty in length which will result in loss to your company. Underweight steels are alway good until they meet the requirement of IS Codes.

As Per IS 1786 the limits for acceptance of steel are

For 8 to 10 mm - +/- 7%

For 12 to 16 mm - +/-5%

For 20 and above - +/- 3%

Thanx for reading

5 comments:

  1. can you explain with example?

    ReplyDelete
  2. For example let's take 8 mm diameter steel whose unit weight is .395 kg per metre. Now you ordered 395 kg steel I.e 1000 meter 8 mm steel.
    After delivery when you cut a 1 meter piece of steel and than weigh it comes .434 kg I.e 10% more.
    So length u received is not 1000 m. It is lesser. Hence you are at loss.

    ReplyDelete
  3. why the rolling margin in IS are different than BSS .can you please elaborate the reason?

    ReplyDelete
  4. Y the margin decreses with increase in dia of bar

    ReplyDelete