Stainless Steel 304 and 316 Sand Casting

Stainless steel 304 and 316 sand casting produces large-format corrosion-resistant components using furan resin-bonded or chemically bonded sand molds, offering a cost-effective route for complex geometry stainless steel parts in weight ranges from 1 kg to 5,000 kg where investment casting is impractical due to size, and forging or fabrication is uneconomical due to complexity. Brass & Copper Parts manufactures SS 304 (CF8) and SS 316 (CF8M) sand castings conforming to ASTM A351, ASTM A743/A744, EN 10283, and BS 3100 standards for pump housings, valve bodies, impellers, manifolds, marine components, and chemical processing equipment. Both no-bake resin sand and green sand processes are available depending on size, quantity, and dimensional requirements.

Product Overview

Sand casting is the dominant process for stainless steel components above 20–30 kg where investment casting tooling and process costs become prohibitive. The process uses disposable sand molds produced from chemically bonded (no-bake furan resin) or CO₂-cured sodium silicate sand, enabling casting of very large and complex components in a single pour. Stainless steel sand castings achieve dimensional tolerances of CT8–CT10 (ISO 8062-3) in the as-cast condition, with CT6–CT7 achievable on machined surfaces after CNC post-processing. Brass & Copper Parts produces SS 304 and SS 316 sand castings in the 1 kg to 2,000 kg range, with pattern equipment in wood, aluminum, and resin-bonded materials for new component introduction and repeat production supply.

Key Features

• Large casting capability – From 1 kg to 2,000 kg per piece in SS 304/316
• ASTM A351 / A743 compliant – CF8, CF8M, CF3M standard cast alloy grades
• Excellent corrosion resistance – SS 316 (CF8M) for chemical, seawater, and acidic environments
• Complex geometry – Internal passages, cores, and complex external shapes achievable
• Full material certification – EN 10204 Type 3.1 with chemical and mechanical test results
• Post-casting machining capability – Complete CNC machining in-house for finished components
• Solution anneal standard – Heat treated at 1050–1100°C water quench as standard for austenitic grades

Technical Specifications

International Grade Equivalents

Product Types and Variants

SS 316 Sand Cast Large Pump Casings and Volutes

Centrifugal pump volutes, casings, and back plates in SS 316 (CF8M) from 5 kg to 500 kg are produced by no-bake sand casting at Brass & Copper Parts for chemical process, seawater desalination, pharmaceutical production, and wastewater treatment applications. No-bake resin sand provides dimensional accuracy CT8–CT9 on complex pump geometries, enabling close-to-drawing hydraulic passage dimensions without extensive handwork. Solution anneal heat treatment at 1050°C with water quench is performed on all CF8M pump castings as standard, restoring full corrosion resistance after casting. Machining to finished bore, face, and flange dimensions is available in-house, with impeller balancing service for rotating components.

SS 304/316 Sand Cast Valve Bodies – Large Format

Large-format gate valves, globe valves, butterfly valves, and check valves in SS 304/316 from DN100 (4″) to DN600 (24″) bore in Class 150 to Class 600 rating are produced as sand castings conforming to ASTM A351 CF8/CF8M and ASME B16.34 dimensional requirements. No-bake sand molds accommodate the complex internal cavity geometries of large valve bodies, including full-bore passages, bonnet chambers, and gland packing recesses, in dimensional tolerances suitable for CNC machining to final valve-assembly dimensions. Brass & Copper Parts produces large valve body sand castings as rough castings, semi-machined, or fully machined and pressure-tested finished valve bodies to order.

SS 316 Sand Cast Marine and Offshore Components

Stainless steel 316 (CF8M) sand castings for marine and offshore applications include large-bore sea chest flanges, impeller housings for seawater lift pumps, thruster body components, and structural brackets for topside equipment. These castings typically range from 20 kg to 2,000 kg, exceeding the practical weight limit of investment casting and requiring the flexibility of sand casting for low-volume production (1–20 pieces per year). Brass & Copper Parts supplies marine stainless sand castings with DNV, Lloyd’s Register, and Bureau Veritas material certification for offshore platform and vessel certification, with spectrometric analysis, mechanical test, and radiographic inspection documentation as required by the classification society.

SS 304/316 Sand Cast Manifolds and Complex Flow Components

Pipeline manifolds, distributor headers, multi-port connector bodies, and subsea tree components in SS 316/316L sand casting enable consolidation of multiple welded pipe and fitting assemblies into single-piece pressure-retaining castings, eliminating weld joint leak paths and reducing hydrostatic test requirements. Sand cast stainless manifold bodies from 10 kg to 500 kg are produced with multiple inlet/outlet ports, instrument connection bosses, and drain/vent connections cored into the casting. Dimensional inspection includes 3D CMM measurement and comparison against CAD model for complex manifold geometries. Brass & Copper Parts offers complete manifold supply including casting, CNC machining, flange facing, pressure testing, and PMI (positive material identification) documentation.

Sand Cast Stainless Steel Impellers for Agitators and Mixers

Agitator impellers, mixer blades, turbine impellers, and propeller-type agitators in SS 304/316 are sand cast for chemical reactor, pharmaceutical bioreactor, waste treatment, and food processing equipment. Large agitator impellers from 200 mm to 2,000 mm diameter and 5 kg to 500 kg are economically produced by sand casting with wooden or aluminum pattern equipment. Dynamic balancing of agitator impellers after machining is performed on computerized balancing machines to G2.5 or G6.3 balance grade as specified. Brass & Copper Parts supplies stainless agitator impellers with full material certification, dimensional inspection, balancing records, and test flange documentation for reactor and vessel manufacturers.

SS 316 Sand Castings for Water and Wastewater Treatment

Municipal water treatment, desalination, and wastewater treatment plants require large stainless steel components — pump casings, valve bodies, filter housings, and strainer bodies — that are cost-effectively produced by sand casting rather than investment casting or fabrication. SS 316 (CF8M) sand castings for water treatment conform to NSF/ANSI 61 where potable water contact is required, with passivation per ASTM A967 and PMI verification as standard for potable water service. Component weights from 5 kg to 1,000 kg are routinely produced, with hydrostatic pressure testing per applicable pump or valve standard (HI, AWWA) as standard for all pressure-retaining castings.

Applications by Industry

Manufacturing Process

SS 304 and 316 sand casting at Brass & Copper Parts uses no-bake (furan resin) chemically bonded sand for dimensional accuracy and clean cavity surfaces essential for stainless steel. Electric arc furnaces (EAF) or induction furnaces melt stainless steel charge materials including stainless scrap, pure alloy additions (Ni, Mo, Cr), and carbon adjustments. Melt chemistry is verified by OES spectrometer before tapping. Pouring temperature is controlled at 1540–1580°C for CF8/CF8M, with pouring speed adjusted for section thickness. Post-casting operations include sand knockout, grinding/fettling, solution annealing (1050°C, water quench), shot blasting, dimensional inspection, spectrometric re-analysis, CNC machining (where specified), and hydrostatic pressure testing. Radiographic examination per ASTM E446/E186 and ultrasonic testing per ASTM A609 are available for critical pressure-retaining components.

Quality Standards and Certifications

• ASTM A351 – CF8, CF8M, CF3M austenitic stainless castings
• ASTM A743 / A744 – Corrosion-resistant castings for general service
• EN 10283 – European stainless steel casting standard
• BS 3100 – British standard for stainless steel castings
• ISO 9001:2015 – Quality management system
• NSF/ANSI 61 – For potable water contact applications
• DNV / Lloyd’s Register / BV – Marine certification for offshore and vessel applications
• EN 10204 Type 3.1 – Material test certificate with every heat

Why Choose Brass & Copper Parts

Brass & Copper Parts combines stainless steel foundry expertise with in-house CNC machining, heat treatment, NDT, and pressure testing to deliver complete stainless steel sand casting solutions. Our no-bake sand system produces dimensionally consistent large-format castings, and our metallurgical laboratory performs real-time melt analysis on every heat before pouring. We maintain an active pattern library for standard pump and valve casting geometries, and our in-house pattern shop produces new wooden and aluminum patterns for new component introductions. We export SS 304/316 sand castings to the UK, Germany, Australia, USA, UAE, and Singapore with full material traceability and shipping documentation.

Frequently Asked Questions

What is the difference between SS 304 and SS 316 sand casting?

SS 304 (CF8) is the standard austenitic stainless with 18% Cr and 8% Ni — suitable for mildly corrosive environments, food contact, and general engineering. SS 316 (CF8M) adds 2–3% molybdenum, providing substantially improved pitting and crevice corrosion resistance in chloride-containing media (seawater, brackish water, many chemical process fluids). SS 316 costs approximately 15–25% more than SS 304. For marine, chemical, and aggressive service, SS 316 (CF8M) is the standard specification.

Why is solution anneal heat treatment important for stainless steel sand castings?

During solidification, carbon combines with chromium to form chromium carbides (M₂₃C₆) at grain boundaries in austenitic stainless steel — a process called sensitization. Sensitization depletes the chromium content near grain boundaries, reducing corrosion resistance and causing intergranular corrosion in aggressive media. Solution annealing at 1050–1100°C dissolves the carbides and rapid water quenching retains carbon in solid solution, restoring full corrosion resistance. All Brass & Copper Parts austenitic stainless castings are solution annealed as standard unless the customer specifies otherwise for high-temperature service grades.

What is the maximum casting weight for SS 316 sand casting?

Brass & Copper Parts produces SS 316 (CF8M) sand castings up to approximately 2,000 kg per piece. The practical limit depends on furnace capacity, handling equipment, and mold size. For castings above 2,000 kg, we partner with specialized heavy stainless steel foundries. Most pump, valve, and marine component castings fall in the 5–500 kg range, which is our primary production zone.

Can SS 316 sand castings be used in seawater service?

Yes, with caveats. SS 316 (CF8M) provides good resistance to flowing clean seawater and splash/spray conditions. However, in stagnant or warm seawater (>25°C), crevice corrosion and pitting can occur in SS 316. For fully immersed seawater service, duplex 2205, super duplex 2507, or titanium are preferred. For intermittent seawater contact, deck hardware, and spray environments, CF8M sand castings are widely specified and perform reliably.

What NDT is available for stainless steel sand castings?

Brass & Copper Parts offers: visual inspection (100%), dimensional check, spectrometric chemical analysis (per heat), mechanical test per ASTM A351 (tensile, yield, elongation), Brinell hardness, hydrostatic pressure test (1.5× working pressure), liquid penetrant test (LPT) for surface defects, radiographic examination (RT) per ASTM E446/E186 for internal soundness, and ultrasonic testing (UT) per ASTM A609. PMI (positive material identification by XRF) is available for individual component material verification.

What is the minimum order quantity for SS 304/316 sand castings?

Brass & Copper Parts accepts SS 304/316 sand casting orders from a single piece for new components where pattern equipment is available. For new patterns (no existing tooling), a minimum of 3–5 pieces per year is typically required to justify pattern manufacture cost. Prototype and development orders (1–2 pieces) are accepted with pattern cost included in the quotation. Production orders start from 5 pieces for standard valve and pump geometries.

How does no-bake sand compare to green sand for stainless steel casting?

No-bake (furan resin bonded) sand produces harder, more rigid molds than green sand, resulting in better dimensional accuracy (CT8–CT9 vs CT9–CT11), superior surface finish (Ra 6.3–12.5 μm vs Ra 12.5–25 μm), and reduced penetration defects on stainless steel castings. Green sand is used for high-volume small stainless castings where cost is the primary driver; no-bake is preferred for larger, more complex components requiring better dimensional consistency and surface quality for subsequent machining.

Request a Quote

Brass & Copper Parts produces SS 304, SS 316, and SS 316L sand castings for pump, valve, marine, chemical, and large engineering applications. Submit your drawing and requirements for a competitive quote with full certification and testing services.

Contact us: sales@brass-copper-parts.com | +91-22-43449300