Rolling Margin for Reinforcement Steel

I don't understand what you meant by "rolling margin". All what I relate to it is "Anchorage depth for bonding". Please explain if my guess is not right.

hi,

my idea regarding rolling margin is the mass per unit length say equal to x kg/mm. what i want to know is standard which explain me that for perticular diameter the mass/unit length shall be ±X now. I am getting steel in + margin ie mass has increased hence i hav to pay more for the weight.

I think you got my question

Reply shall be appreciated.

Thanks

Dear Shafimj,

Your concept is quite OK. Let me elborate. Each & Every type of commonly used steel has its standard weight per unit length. This includes Plates, Bars, Sheets, Reinforcement etc etc. Now over a period of time, the manufacturers mold for moulding / rolling these products gets worn out, rather increases. This process entails the usage of more raw material for the same length and dimension of the processed steel product. This further results in issue of more weight of the material against the given parameters of dimensions including length of the material.

In the Industry where steel is used, the approving authority or the client usually approves the quantity used in terms of length or dimensions, BUT NOT AGAINST THE WEIGHT USED. This thus leads to the issue of more weight of a steel material for a process vis-a-vis' its length. Such a circumstance is undesirable, as the issuing company has to pay more for the same length of steel. Further Rolling Margin can be negative or positive depending if the unit weight for a particular length is less or more. In the industry , negative rolling margin is desired, though it never happens that way. Generally we end up getting steel with a positive rolling margin. The standard formula for arriving at the weight mer meter for lengthy sections of steel is as given below;

Where D = Diameter of the Steel

I hope I have managed to clarify myself of the lingering doubt of many. Ask more in case required.

GPoonjatt

Dear Sir,

Your reply is excellent but can you explain how that +ve or -ve weight calculate for steel reconciliation?

Regards,

Vyas

Neither did I. Had difficulty comprehending an encrypted english grammar.

Me Tarzan, you Jane.

For rebar, the tolerance for mass/length (kg/meter) is + or -6%.

what are the basics of rolling Margin used for concreting reinforcement

Hi

You Are Totally wrong. Rolling margin is the mass per unit length

Presently I could not access my literature to give you some of these rates but you could visit this website www.steelforge.com for your queries.

Hi.

Thanks for your guidence.

With regards

Rolling margin plays a very important role in steel accounting. To clarify this matter, let me explain it further. All and every type of steel, whether in Bars, Sheets, Angles or any other form is expressed in a standard size and weight. This is generally expressed in Kgs/Meters, and comes in a standardised pattern. For example, for reinforcement steel type FE 415 6mm Bar teh standard weight per meter is .322 Kgs/Meter. With this measurement one can measure the complete quantity of steel for a particular length recieved by him. This measurement is universally standard, though manufacturers when supplying the item deliver in varying weight to the customer.

This is basically due to the reason that over a period of time, even the mould at the manufacturers end gets distorted due to constant use and hence the above mentioned standardisation does not hold good. This leads to the incorrect usage reporting at the construction level, and the complete material inventory of the user does not present a correct picture.

Further, even the Rolling Margin can be -ve or +ve. When it weighs lesser than the standard weight, then it is -ve otherwise it is termed as +ve.

Doing industrial experience in a steel mill 30 years ago, the operators tended to adjust to positive rolling margin.

The operators were paid bonus per ton processed and the steelworks sold by the ton.

Some other shapes had bonus calculated by length and you can bet those were rolled at minus margin to get maximum lenght for each billet processed.