What is a rolling margin in reinforcement steel

[Srinivasan]

What is rolling margin in reinforcement steel ?
Rolling margin in reinforcement steel is percentage of deviation in Sectional weight of Reinforcement steel allowable as per IS codes. Reinforcement steel is extruded from a die which is made for a particular size example 8mm Dia. When the die is brand new, the sectional weight of 8mm steel extruded through die would exact as per IS standard of lower than i.e. 0.395Kg per Meter or lessor. Die gets little bigger after
certain period of time or after certain quantity of production is taken from a particular die. Now same 8mm dia bars extruded from the same die will have more weight per Meter say 0.400 Kg per Meter instead of 0.395 as per IS. That is more mass per Meter/Length is required for same length. This deviation in weight is defined in IS codes for different dia which is as under :-



Allowable deviation in rolling margin in reinforcement steel as per Indian Standards 1786 - 2008 for a Batch
8mm to 10mm +/- 7%
12mm to 16mm +/- 5%.
20mm and above +/-3%.

Rolling Margin is calculated as under :-
Total Weight of Bars (Dia wise ) / Total Running Meter of Bars = Actual Sectional Weight of bars.
Compare sectional weight with Standard IS Weight.

Rolling Margin:
• Length of one rod from each diameter is to be measured and written in Stock Register.
• Weight of rods vary from the standard weight.
• Calculating the weight of steel based on the sample unit weight is necessary to avoid manipulation by the Supplier.
• This actual weight of steel is required for the periodical Reconciliation of Steel.
• Say, for example

100 MT of 16mm Ø bars of Fe500 grade are required to procure. Assume the weight of bar received is 1.63 kg/Rm.
Total Weight of Steel received = 100,000 kg
Standard Weight of Steel = 1.58 kg/m
Length of Steel received = 100,000 / 1.63 = 61,349.693 m

But the length of Steel as per Standard weight = 100,000 / 1.58 = 63,291.139 m
Loss of Weight = ( 1.63 – 1.58 ) / 1.58 = 3.16 %

This is the Rolling Margin in Reinforcement Steel.

Weight computed by measurement & Standard weight = 61,349.693 x 1.58 = 96,932.50 kg

Loss of Weight = 100,000 – 96,932.50 = 3067.50 kg

 

[mdali]

Very good information

 

[Pk27feb]

What is rolling margin in reinforcement steel ?
Rolling margin in reinforcement steel is percentage of deviation in Sectional weight of Reinforcement steel allowable as per IS codes.Reinforcement steel is extruded from a mould which is made for a particular size e.g 8mm Dia. When the mould is brand new,the sectional weight of 8mm steel extruded through mould would exact as per IS standard of lower than that.i.e. 0.395Kg per Metre or lessor. Mould gets little bigger after
certain period of time or after certain quantity of production is taken from a particular mould. Now same 8mm dia bars extruded from the same mould will have more weight per Metre say 0.400Kg per Metre instead of 0.395 as per IS. That is more mass per Metre/Length is required for same length.This diviation in weight is defined in IS codes for different dia which is as under :-

Allowable deviation in rolling margin in reinforcement steel as per indian standards 1786-1985 for a Batch
8mm to 10mm +/- 7%
12mm to 16mm +/- 5%.
20mm and above +/-3%.

Rolling Margin is calculated as under :-
Total Weight of Bars (Dia wise ) / Total Running Metre of Bars = Actual Sectional Weight of bars.
Compare sectional weight with Standard IS Weight.

Rolling Margin:
• Length of one rod from each diameter is to be measured and written in Stock Register.
• Weight of rods vary from the standard weight.
• Calculating the weight of steel based on the sample unit weight is necessary to avoid manipulation by the Supplier.
• This actual weight of steel is required for the periodical Reconciliation of Steel.
• Say, for example

100 MT of 16mm Ø bars of Fe500 grade are required to procure. Assume the weight of bar received is 1.63 kg/Rm.
Total Weight of Steel received = 100,000 kg
Standard Weight of Steel = 1.58 kg/m
Length of Steel received = 100,000 / 1.63 = 61,349.693 m

But the length of Steel as per Standard weight = 100,000 / 1.58 = 63,291.139 m
Loss of Weight = ( 1.63 – 1.58 ) / 1.58 = 3.16 %

This is the Rolling Margin in Reinforcement Steel.

Weight computed by measurement & Standard weight
= 61,349.693 x 1.58 = 96,932.50 kg

Loss of Weight = 100,000 – 96,932.50 = 3067.50 kg

Dear sir I don't understand calculation about -
Weight computed by measurement & standard weight???
Lenght of steel received how it's is calculated?
How is it calculated?

 

[sachin0102]

Why this rolling margin occurs
I mean it is negative and positive both.. .. How??
When negative and when positive and why??

 

[Jof Joseph]

Can i have a format for the calculation and reconciliation of steel?

 

[MAR]

What is rolling margin in reinforcement steel ?
Rolling margin in reinforcement steel is percentage of deviation in Sectional weight of Reinforcement steel allowable as per IS codes.Reinforcement steel is extruded from a mould which is made for a particular size e.g 8mm Dia. When the mould is brand new,the sectional weight of 8mm steel extruded through mould would exact as per IS standard of lower than that.i.e. 0.395Kg per Metre or lessor. Mould gets little bigger after
certain period of time or after certain quantity of production is taken from a particular mould. Now same 8mm dia bars extruded from the same mould will have more weight per Metre say 0.400Kg per Metre instead of 0.395 as per IS. That is more mass per Metre/Length is required for same length.This diviation in weight is defined in IS codes for different dia which is as under :-

Allowable deviation in rolling margin in reinforcement steel as per indian standards 1786-1985 for a Batch
8mm to 10mm +/- 7%
12mm to 16mm +/- 5%.
20mm and above +/-3%.

Rolling Margin is calculated as under :-
Total Weight of Bars (Dia wise ) / Total Running Metre of Bars = Actual Sectional Weight of bars.
Compare sectional weight with Standard IS Weight.

Rolling Margin:
• Length of one rod from each diameter is to be measured and written in Stock Register.
• Weight of rods vary from the standard weight.
• Calculating the weight of steel based on the sample unit weight is necessary to avoid manipulation by the Supplier.
• This actual weight of steel is required for the periodical Reconciliation of Steel.
• Say, for example

100 MT of 16mm Ø bars of Fe500 grade are required to procure. Assume the weight of bar received is 1.63 kg/Rm.
Total Weight of Steel received = 100,000 kg
Standard Weight of Steel = 1.58 kg/m
Length of Steel received = 100,000 / 1.63 = 61,349.693 m

But the length of Steel as per Standard weight = 100,000 / 1.58 = 63,291.139 m
Loss of Weight = ( 1.63 – 1.58 ) / 1.58 = 3.16 %

This is the Rolling Margin in Reinforcement Steel.

Weight computed by measurement & Standard weight
= 61,349.693 x 1.58 = 96,932.50 kg

Loss of Weight = 100,000 – 96,932.50 = 3067.50 kg

Good information

 

[MAR]

What is rolling margin in reinforcement steel ?
Rolling margin in reinforcement steel is percentage of deviation in Sectional weight of Reinforcement steel allowable as per IS codes.Reinforcement steel is extruded from a mould which is made for a particular size e.g 8mm Dia. When the mould is brand new,the sectional weight of 8mm steel extruded through mould would exact as per IS standard of lower than that.i.e. 0.395Kg per Metre or lessor. Mould gets little bigger after
certain period of time or after certain quantity of production is taken from a particular mould. Now same 8mm dia bars extruded from the same mould will have more weight per Metre say 0.400Kg per Metre instead of 0.395 as per IS. That is more mass per Metre/Length is required for same length.This diviation in weight is defined in IS codes for different dia which is as under :-

Allowable deviation in rolling margin in reinforcement steel as per indian standards 1786-1985 for a Batch
8mm to 10mm +/- 7%
12mm to 16mm +/- 5%.
20mm and above +/-3%.

Rolling Margin is calculated as under :-
Total Weight of Bars (Dia wise ) / Total Running Metre of Bars = Actual Sectional Weight of bars.
Compare sectional weight with Standard IS Weight.

Rolling Margin:
• Length of one rod from each diameter is to be measured and written in Stock Register.
• Weight of rods vary from the standard weight.
• Calculating the weight of steel based on the sample unit weight is necessary to avoid manipulation by the Supplier.
• This actual weight of steel is required for the periodical Reconciliation of Steel.
• Say, for example

100 MT of 16mm Ø bars of Fe500 grade are required to procure. Assume the weight of bar received is 1.63 kg/Rm.
Total Weight of Steel received = 100,000 kg
Standard Weight of Steel = 1.58 kg/m
Length of Steel received = 100,000 / 1.63 = 61,349.693 m

But the length of Steel as per Standard weight = 100,000 / 1.58 = 63,291.139 m
Loss of Weight = ( 1.63 – 1.58 ) / 1.58 = 3.16 %

This is the Rolling Margin in Reinforcement Steel.

Weight computed by measurement & Standard weight
= 61,349.693 x 1.58 = 96,932.50 kg

Loss of Weight = 100,000 – 96,932.50 = 3067.50 kg

Good information shared