"Rolling margin" functionality allows you to adjust the weight of your rebar and plain items throughout the system based on the fact that dies and rollers used to produce stock steel wear down over time. This is a common practice in Australia. 

Background

Most rebar is produced by taking billets from the electric arc furnace or blast furnace technologies and repeatedly passing them through large rollers that "squeeze" or "roll" the infeed material into the desired profile.

This is not an exact science: the dies and rollers wear with age and the finished product typically varies in diameter throughout its length. Relevant standards allow this variation in terms of prescribed percentage differences from nominal.

You (the fabricator) purchase rebar based on a standard weight, calculated as kilograms/meter or pounds/foot. With the understanding that the rollers and dies used to produce that rebar often become worn, resulting in slightly heavier bars, you may elect to sell the material to your customer based on a slightly higher weight than the standard. 

To calculate rebar item weights when you apply rolling margin, the system:

  • Multiplies the material length by the industry standard weight/length value (see special case below)
  • Adds the rolling margin percentage if applicable

Examples

Imperial Example:

  • The standard factor for a size 8 bar is 2.6700 pounds/foot.
  • Based on this weight factor, a 60-00 size 8 bar is 160.2 pounds. 
  • With a 1.5% rolling margin applied, the same bar will be stored and displayed throughout the system as 162.6 pounds.

Metric Example:

  • The standard factor for a size 35mm bar is 7.8500 kilograms/meter
  • Based on this weight factor, a 1,800 mm size 35mm bar is 14.13 kilograms.
  • With a 1.5% rolling margin applied, the same bar will be stored and displayed throughout the system as 14.34 kilograms.

Additional Notes

Rolling margins are handled like other defaults.

For example, a rolling margin set up at the Business Partner level becomes the default for any new jobs you create for that customer. At the job level, you can override the default and set it something different. Likewise, the job default rolling margin becomes the default at the Order Entry level, where it can be overridden if necessary. 

Once applied, rolling margins affect all rebar and plain weights from that point forward

For example, if you apply a 2% rolling margin to an order, weights of all the bars on that order will appear 2% heavier on the Order Detail report, tags, and all Processing reports. Likewise, the exact same quantity and material on another order may have a different weight if a different — or no  — rolling margin was applied to it. 

Inventory Weights

  • Rolling margin does not apply to weights in Inventory Tracking (barcoding). 
  • Inventory Managment (accounting) weight is relieved with any applicable rolling margin applied. 

Importing and Exporting

When you export orders to RDX format, the files will include any relevant rolling margin data. When you import from RDX, the rolling margin data is saved in the database with the imported information.