In-House Shot Blasting, Shapar, Rajkot
Shivam Forge runs rotary tumble and hook-type shot blasting machines at our Shapar, Rajkot plant. We blast to ISO 8501-1 standards — Sa 2.5 near-white and Sa 3 white metal available — using steel shot and grit for scale removal, pre-plating prep, pre-NDT, and pre-paint surface preparation. Call +91-9265772827 for capacity and pricing.
Shot blasting is not a finishing step — it is the foundation of every downstream process. Zinc plating adhesion, magnetic particle inspection reliability, paint film bonding, NDT indication clarity: all of them depend on getting the surface clean and at the right roughness profile before the component moves on. Our in-house shot blasting capability means forgings from the press shop are blasted, inspected, and ready for next-step processing without leaving the Shapar campus. We handle small forgings up to 20 kg on the rotary tumble machine and larger components up to 300 kg on the hanger/hook type. Steel shot and grit are selected to suit the required surface profile — Sa 2.5 and Sa 3 are routinely achieved.
Shot blasting before heat treatment removes loose scale and decarburised surface layer from as-forged components, giving consistent surface response to quenching and reducing the risk of soft spots from retained scale.
Zinc plating adhesion is destroyed by scale, oxide, and rust. Shot blasting to Sa 2.5 before plating gives a clean, active surface that chromate passivation adheres to correctly, ensuring full salt-spray performance.
Paint adhesion to steel is governed by surface cleanliness and anchor profile. Sa 2.5 with an Rz of 40–60 microns is the standard requirement for epoxy and powder-coat systems on structural and machinery components.
Magnetic particle inspection (MT) and ultrasonic testing (UT) require a clean, scale-free surface to detect surface and sub-surface discontinuities reliably. Shot blasting to Sa 2 or Sa 2.5 is standard pre-NDT preparation.
Components that have been stored or are in transit can develop light to heavy rust. Shot blasting to Sa 2.5 restores the surface to near-white metal, ready for immediate re-coating or further processing.
Some customers want a uniform, attractive grey shot-blasted finish on visible components without painting. Our Sa 2.5 shot blast finish with S230 shot gives a consistent, even appearance across the forged surface.
Tumble blasting rotates small forgings in a chamber while blast wheels throw steel shot/grit at the surface from multiple angles. Efficient for small components, fasteners, and forgings with no fragile projections.
Larger forgings — flanges, yokes, axle shafts, gear blanks — are hung on rotating hooks inside the blast chamber. Blast coverage is all-round with consistent Rz profile across the part surface.
S170 and S230 cast steel shot are used for standard scale removal and surface finishing. Harder shot (S280, S330) is available for aggressive de-scaling of heavy forgings with thick oxide layers from high-heat forging.
Angular steel grit cuts into heavy scale and rust more aggressively than spherical shot and produces a higher anchor profile. G25 and G40 grit is used for components with heavy forge scale or where maximum Rz is needed for paint adhesion.
ISO 8501-1 visual grades from Sa 1 (light blast) to Sa 3 (white metal, 100% clean surface) are achievable. Sa 2.5 is our most commonly requested grade — near-white metal with 95%+ of each unit area free of contamination.
Surface roughness (anchor profile) is controlled by abrasive selection, shot size, and wheel speed. We achieve Rz 30–75 microns as required. Profile is verified with Testex Press-O-Film tape and reported to the customer.
ISO 8501-1 is the international standard for visual assessment of surface cleanliness. We assess each batch against photographic reference comparators and record the achieved grade on the process traveller.
American SSPC-SP 10 near-white metal blast is equivalent to ISO 8501-1 Sa 2.5 and is specified by many paint and coating manufacturers for structural steel, offshore, and pipeline applications.
Automotive forgings are blasted before zinc plating, zinc phosphating, or e-coat priming. We coordinate shot blasting, plating, and machining in sequence to minimise handling and ensure dimensional integrity.
Forged pipe fittings, flanges, and valves destined for fusion-bonded epoxy (FBE) or liquid epoxy coating require Sa 2.5 minimum with controlled Rz profile before coating. We meet the FBE applicator's surface spec.
Pump casings, gearbox housings, shaft components, and general engineering forgings blasted before painting or final inspection. We handle both one-off and batch production for industrial machinery manufacturers.
Foundation and anchor bolt forgings blasted before hot-dip galvanising or zinc plating for construction projects. Clevis hooks and lifting hardware blasted before NDT inspection as part of safe working load certification.
Shot blasting is the one surface preparation process that affects the quality of everything that comes after it. Paint adhesion, NDT reliability, plating bond strength, phosphate conversion coat uniformity — all of them depend on a clean, profiled surface. Yet many small forges outsource blast cleaning, which means components travel off-site, accumulate handling marks, and sometimes re-oxidise before reaching the plating or coating line. At Shivam Forge, shot blasting is an in-house process integrated directly into the manufacturing sequence. Forgings leave the press shop, go to blast cleaning, then move directly to whatever comes next — plating, heat treatment, or NDT inspection — without leaving the Shapar campus.
Our two blast machines cover the full size range of components we produce. The rotary tumble machine handles small forgings — fasteners, pins, small gear blanks, and clevis components — in batches up to 200 kg, cycling through the blast chamber and inspected for Sa 2.5 cleanliness before dispatch to the next operation. The hook/hanger machine handles larger forgings: flanges, yokes, connecting rods, axle shafts, and custom components up to 300 kg individual weight. Components hang on jigs that rotate within the blast cabinet, ensuring all-round coverage without manual repositioning. Both machines use calibrated blast wheels with controlled shot flow and velocity — not manual pressure blasting, which gives inconsistent results.
Abrasive selection is not an afterthought. Steel shot (S170, S230) gives a smooth, peened surface with Rz 30–45 microns — ideal before zinc plating, phosphating, or e-coat primer. Steel grit (G25, G40) cuts an angular, high-profile surface with Rz 45–75 microns — what epoxy primer manufacturers and FBE coating applicators typically specify for oil & gas pipe components. We confirm achieved surface profile using Testex Press-O-Film tape and include the profile measurement in the blast inspection record. This is the level of process discipline that oil & gas and construction customers expect — and that most local blasting shops do not provide.
Industries served span the full range of our forging output. Automotive customers blast before zinc plating or zinc phosphate conversion for paint. Oil & gas customers blast flanges and pipe fittings before FBE or liquid epoxy coating. Agricultural equipment manufacturers blast tractor linkage components before paint. Construction hardware manufacturers blast anchor bolts and hooks before hot-dip galvanising or zinc plating. In every case, coordinating blast cleaning with forging and subsequent processing at a single facility saves time, reduces handling damage, and gives you a single quality record from billet to finished surface.
To discuss shot blasting capacity for your forged components — whether you need integrated forge-blast-plate supply or standalone blast cleaning on customer-supplied parts — call Shivam Forge at +91-9265772827 or email info@shivamforge.com. Our facility is in Shapar, Rajkot, Gujarat, well-located for road transport across western India. We will respond to enquiries within 24 hours with pricing, capacity, and scheduling options.
Yes. Shivam Forge has in-house shot blasting capability at our Shapar, Rajkot plant — rotary tumble blasting for small components and hook/hanger type for larger forgings up to 300 kg.
Sa 2.5 is ISO 8501-1 near-white metal blast. At least 95% of the surface area is free from scale, rust, paint, and other contamination when viewed without magnification. A light shadow, streaks, or discolouration from stains is permissible. It is the standard requirement before high-performance paint or zinc plating.
Rotary (tumble) blasting tumbles components in a drum — suitable for small, robust parts like fasteners and small forgings. Hook-type blasting suspends individual components from rotating hooks inside the blast chamber — better for larger, heavier, or more fragile parts that cannot be tumbled.
Steel shot is spherical and produces a peened, low-anchor-profile surface suitable for standard coatings and scale removal. Steel grit is angular and cuts into the surface more aggressively, producing a higher anchor profile (Rz) better for high-build epoxy or FBE coatings. We select the abrasive based on your coating specification.
Yes. Shot blasting before zinc plating is a standard step in our workflow. Components are blasted to Sa 2.5, inspected, and moved immediately to the plating line to prevent re-oxidation. This sequence ensures maximum plating adhesion and salt-spray performance.
Yes. Sa 3 white metal blast — 100% clean surface, steel with uniform metallic colour — is achievable on our hook-type machine using steel grit. It is required for thermal spray coatings and some high-performance paint systems. Sa 3 is slower and more expensive than Sa 2.5; specify only where your coating system requires it.
We handle batches from 10 kg upward. Our rotary line handles small batches efficiently; hook-type is better for single large components. Contact us at +91-9265772827 to discuss batch sizes and scheduling.
Email info@shivamforge.com with part name, approximate size and weight per piece, current surface condition, required ISO 8501-1 grade, downstream process (plating / painting / NDT), and quantity. We respond within 24 hours.
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.
