new 304 stainless steel mixer impeller outer diameter-70MM inner hole-8MM

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What Is the 304 Stainless Steel Mixer Impeller (70mm OD / 8mm ID)?

In short: This is a new 304-grade stainless steel mixing impeller with a 70 mm outer diameter and an 8 mm inner bore, designed to mount on a motor shaft for blending liquids, suspending solids, or agitating process fluids in tanks and vessels across food, chemical, and pharmaceutical industries.

The impeller is the heart of any stirred tank — its diameter, blade geometry, and material composition determine how efficiently your mixture achieves uniformity. This 70 mm OD impeller in 304 stainless steel strikes a practical balance: large enough to move meaningful fluid volume in bench-scale and pilot-plant vessels, yet compact enough to spin at the higher RPM ranges common with small-frame electric stirrer motors. The 8 mm bore fits a standard shaft diameter found on many laboratory and light-industrial mixer drives.

Grade 304 stainless is chosen for its excellent all-around corrosion resistance — it handles water-based solutions, mild acids, many organic solvents, and food-contact environments without rusting or leaching. This makes the impeller suitable for recipe development in food labs, pH adjustment tanks in water treatment, paint and coating mixing, and small-batch pharmaceutical compounding. The welded hub construction ensures concentricity with the shaft, minimizing vibration that can wear out motor bearings prematurely.

Before ordering, confirm that your mixer shaft diameter matches the 8 mm bore. A slight interference fit with a set-screw or keyway is standard for secure mounting. If your shaft is metric 8 mm or a close imperial equivalent (5/16 inch = 7.94 mm), this impeller should slide on with minimal adjustment. Contact us if you need a different bore size — we may have alternatives in stock.

Technical Specifications

Frequently Asked Questions

Can this impeller handle corrosive chemicals like sulfuric acid?

304 stainless steel resists many chemicals but has limits. It performs well with organic acids, alkaline solutions, and most food products. However, it is not recommended for prolonged contact with concentrated sulfuric or hydrochloric acid, which can cause pitting corrosion. For aggressive chemical service, 316L stainless or Hastelloy impellers may be more appropriate. If you are unsure about chemical compatibility, send us your process fluid details and we can advise.

How do I secure this impeller to my mixer shaft?

The 8 mm bore slides onto a matching shaft diameter. Most installations use either a set-screw threaded into the impeller hub that tightens against a flat on the shaft, or a keyway slot that engages a square key between shaft and hub. Check whether your impeller has a set-screw provision — if not, a shaft collar tightened above and below the impeller can lock it in position. Avoid using adhesives alone, as they may fail under shear load.

What tank size is this 70 mm impeller suited for?

As a rule of thumb, an impeller diameter of roughly one-third the tank diameter provides good bulk mixing. This 70 mm impeller is therefore well-suited to vessels in the 200-300 mm diameter range — typically 5 to 20 liter bench-scale reactors or mixing tanks. For larger vessels, you would either scale up the impeller diameter proportionally or use multiple impellers on the same shaft.

Is this impeller food-grade and FDA compliant?

304 stainless steel is generally recognized as safe for food contact and is widely used in dairy, beverage, and food processing equipment. The surface finish determines cleanability — a polished finish resists biofilm adhesion better than a rough mill finish. If you require certified food-grade documentation (e.g., 3A sanitary standards), please request it at the time of inquiry so we can verify the material certification for this batch.

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