Calpeda 14003670000 Impeller Key - 5 x 5 x 15 mm AISI 316
The Calpeda 14003670000 is the genuine impeller key in AISI 316 stainless steel, measuring 5 x 5 x 15 mm and made to UNI 6604. It locks the impeller to the pump shaft, sitting half in the shaft keyway and half in the impeller boss so that motor torque reaches the impeller rather than the shaft simply spinning inside it.
The material is the point of difference here, and it is not a cosmetic upgrade. An impeller key lives inside the wet end, permanently immersed in whatever the pump is moving, and in a half-open keyway it sits in a crevice where liquid stagnates and oxygen is scarce. That is punishing duty for plain carbon steel, which rusts, swells in the keyway and then either seizes the impeller onto the shaft or corrodes away until it is a loose fit. AISI 316 is the marine-grade austenitic stainless, alloyed with molybdenum specifically to resist chloride attack, which is why Calpeda specifies it for pumps handling seawater, brackish water and aggressive liquids where a plain steel key would not last a season.
Practically, treat it the way you would any drive key. It should slide into the keyway under hand pressure with a snug fit across the width, never be driven in. Check both keyways for wear before you assemble, since a new key in a spread slot will simply work its way loose again. And keep the materials consistent through the assembly - pairing a 316 key with a stainless shaft and a stainless impeller nut avoids setting up a galvanic couple in the one part of the pump that is permanently wet.
Key Features
- Genuine Calpeda spare part
- AISI 316 stainless steel - molybdenum-alloyed for chloride and seawater resistance
- 5 x 5 x 15 mm parallel key to UNI 6604
- Will not rust, swell in the keyway or seize the impeller to the shaft
- Suited to the stagnant, low-oxygen crevice conditions inside a keyway
- Matches stainless shafts and stainless impeller nuts without galvanic mismatch
Applications
- Calpeda centrifugal pumps using a 5 x 5 x 15 mm impeller key
- Seawater, brackish water and other chloride-bearing duties
- Bronze and stainless pump builds where a plain steel key is not appropriate
- Replacing a corroded or seized key found during an impeller change
- Marine and dockside installations and workshop spares stock
- Industrial and agricultural pumps handling aggressive liquids
Specifications
- Brand: Calpeda
- Manufacturer: Calpeda Spa
- Manufacturer Part Number: 14003670000
- Part Type: Impeller key, parallel
- Dimensions: 5 x 5 x 15 mm
- Material: AISI 316 stainless steel
- Standard: UNI 6604
- Quantity Used: One per impeller
- Condition: New
Frequently Asked Questions
Q: Is a stainless key weaker than a carbon steel one?
In raw tensile terms 316 is softer than a hardened carbon steel key, but in a pump the key is sized with a generous margin and corrosion is the far likelier cause of failure. Where the manufacturer specifies stainless, the corrosion resistance is worth more than the extra strength.
Q: How do I tell 316 from ordinary stainless once it is fitted?
You cannot reliably tell by eye, which is exactly why the part number matters. Keep spares in their labelled packaging rather than loose in a drawer with other keys, because a mixed handful of keys is impossible to sort afterwards.
Q: My old key is stuck solid in the shaft keyway. How do I get it out?
Penetrating oil and patience first, then gentle leverage from one end with a small drift. Resist the urge to chisel it, because damage to the keyway walls is far more serious than the key itself and is not something you can dress out afterwards.
Q: Do I need to fit a stainless key if my pump came with a plain one?
Not necessarily, but it is a sensible upgrade for anything in a salt or brackish environment. Just confirm the dimensions match your keyway - the material can change, but 5 by 5 by 15 has to be right.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct key size before you order.
CLRMarine
