How to Choose the Right Billet Size for Forging and Rolling
A method to match billet or bloom section to the finished forging or rolled section, using reduction ratio and yield.
Start from the finished part
Find the forged weight of the part, including machining allowance. Add scale loss and cut-off losses to get the billet weight you need.
Pick the section
Choose a billet section that gives the reduction your process needs. For small forgings, 100 or 125 mm squares work. For medium forgings, 160 mm. For rings and heavier parts, 200 or 250 mm blooms or 200 mm round.
Check the reduction ratio
The reduction ratio is the starting cross-section divided by the finished cross-section. Many specifications ask for a minimum, so follow yours. Too small a section gives low reduction and weaker properties.
Consider length and handling
Billets up to 12 metres reduce cutting loss and handling. Order cut lengths if your furnace and saw are set for them.
Ask the supplier
Send the drawing, grade and the press or mill capacity. Kesari Alloys can recommend a section and confirm the available length.
Related guides
How to Calculate Steel Billet Weight (Formula and Examples)
Formulae for the weight of square and round steel billets and blooms, with worked examples.
Reduction Ratio: Why It Matters When Rolling or Forging Billets
How the reduction ratio between billet and finished section affects soundness, grain and ultrasonic test results.
What Is a Steel Billet? Sizes, Grades and Uses
A plain guide to steel billets: how they are made, typical sizes, grades and where they are used.
Billet size chart · Weight calculator · Steel grade directory