Cold Sizing & Coining Services — Precision Post-Forging Cold Restrike Bringing As-Forged Features to Final Tolerance Without Machining
Shivam Forge provides cold sizing and coining services — a room-temperature restrike operation performed in a dedicated sizing die after hot forging, bringing specific as-forged features to tight final dimensional tolerance without the material removal, cycle time, and cost of full CNC machining. Rajkot, India. Call +91-9265772827.
Cold sizing (also called coining or restriking) takes a component that has already been hot forged, cooled, and typically heat treated, and puts it through one further forming operation — this time at room temperature, in a precision sizing die — that compresses specific features to their exact final dimension through continued plastic deformation rather than material removal. This is a genuinely different approach to closing the gap between as-forged dimensional tolerance and a component's final specification than the default alternative, CNC machining: where machining removes material with a cutting tool to reach final dimension, cold sizing squeezes the already-near-net-shape feature the remaining small amount into tolerance, retaining the material (and its favorable as-forged grain flow) rather than cutting it away. The practical case for cold sizing over full machining is strongest precisely where it applies best: specific flat faces, thickness dimensions, or simple bore or boss features that only need to move a small, controlled amount to reach final tolerance, where a dedicated sizing die can close that gap in a single fast press stroke considerably faster and cheaper per piece than setting up and running a CNC operation to machine the same feature — while also work-hardening the surface slightly and improving surface finish as a side effect of the cold deformation itself.
Cold sizing of flat forging faces and overall part thickness dimensions, compressing these features to final tolerance in a single press stroke rather than requiring a face-milling or surface-grinding machining operation.
Cold sizing of forged bore diameters or boss features where the as-forged dimension is close enough to final tolerance that a sizing operation, rather than boring or reaming, can economically close the remaining gap.
Coining operations applying high localized pressure to sharpen specific as-forged detail features or improve flatness on functional faces, beyond what the original forging die impression alone achieves.
Sizing die design addressing multiple dimensionally critical features of a single component in one restrike operation, minimizing the number of separate post-forging operations required to reach final specification.
Engineering assessment of which specific component features are genuinely suited to cold sizing versus requiring full CNC machining — sizing works best where the as-forged-to-final dimensional gap is small and controlled, not as a substitute for features needing substantial stock removal.
Dedicated sizing die tooling designed for each component's specific features requiring size correction, engineered to apply controlled restrike force without introducing new flash or unwanted deformation elsewhere on the part.
Post-sizing dimensional verification confirming sized features meet the specified final tolerance, using the same inspection methods applied to machined dimensional features.
Guidance combining cold sizing for suitable features with targeted CNC machining for features requiring tolerances or geometry beyond what sizing alone can achieve, optimizing the overall post-forging process cost.
Cold sizing occupies a genuinely useful middle position in the sequence of operations that take a hot forging from its as-formed dimensional tolerance to a component's final specification, and understanding when it applies — and when it doesn't — helps avoid defaulting unnecessarily to full CNC machining for features that don't actually require it. The core idea is straightforward: rather than cutting material away to reach a final dimension, cold sizing places the already near-net-shape forging back into a precision die at room temperature and applies enough compressive force to further deform the specific feature in question the remaining small amount needed to hit final tolerance, retaining every gram of material at that feature rather than removing it as chips.
This retained-material characteristic carries two genuine, distinct benefits beyond simply avoiding a machining operation. First, because no material is cut away, the favorable grain flow the original hot forging established at that feature remains intact rather than being interrupted by a cutting tool passing through it — a real, if secondary, benefit for features where fatigue performance matters. Second, the cold deformation involved in sizing work-hardens the surface layer slightly and can measurably improve surface finish compared to the as-forged condition, a useful side effect for functional faces or sealing surfaces where a smoother finish is valuable, achieved here as a byproduct of the forming operation itself rather than requiring a separate finishing step.
The economic case for cold sizing is strongest, and most defensible, specifically where the gap between as-forged dimension and final tolerance is genuinely small and controlled — flat faces needing tight thickness or flatness tolerance, bosses or bores needing a modest final diameter correction. In these cases, a dedicated sizing die closes the gap in a single fast press stroke, at a cycle time and cost per piece considerably below what setting up and running an equivalent CNC operation would require. Where the required dimensional change is larger, or the feature's geometry is complex enough that forming alone can't reliably reach it, machining remains the correct and necessary approach — cold sizing is a genuine cost and cycle-time optimization for the right features, not a universal substitute for machining.
For manufacturers looking to reduce machining cost and cycle time on forged components with well-defined final-tolerance features, Shivam Forge provides cold sizing and coining services alongside our standard CNC machining capability. Contact our engineering team at +91-9265772827 or sales@shivamforge.com with your component drawing to discuss which features are suited to cold sizing and to receive a combined process quotation.
Cold sizing brings an as-forged feature to final tolerance by further plastic deformation in a precision die at room temperature, without removing any material. CNC machining reaches final tolerance by cutting material away with a tool. For features where the as-forged dimension is already close to final tolerance, sizing is typically faster and cheaper per piece than machining; for features requiring substantial stock removal or complex geometry, machining remains necessary.
No — cold sizing works best on features where the gap between as-forged dimension and final specification is small and controlled, such as flat faces, thickness dimensions, or simple bore and boss features. Features requiring substantial material removal, complex three-dimensional machining, or fine surface finish typically still require CNC machining; we assess feature suitability on a component-by-component basis.
Cold sizing retains the material at the sized feature rather than cutting it away, preserving the favorable as-forged grain flow that machining a feature down to size would otherwise interrupt. The cold deformation also work-hardens the surface slightly, which can be a beneficial side effect for wear or fatigue performance depending on the application.
This depends on the component and the specific dimensional requirement — sizing can be performed after heat treatment to correct any heat-treatment-related dimensional shift, or as a standalone post-forging operation ahead of heat treatment, depending on which sequence best achieves the final specification for a given feature. Our engineering team advises on the correct sequence for your component.
For some components with modest, well-controlled dimensional requirements on flat faces or simple features, sizing alone can eliminate the need for machining those specific features. Most components still combine sizing for suitable features with targeted machining for others; we can review your drawing and recommend the most cost-effective combination.
Why Choose Shivam Forge
Shivam Forge delivers precision hot-forged components from our integrated Shapar, Rajkot facility — covering forging, CNC machining, heat treatment, and quality inspection under one roof.
