Yamada 621213 Bolt for NDP-50
The Yamada 621213 is the genuine bolt for NDP-50 Series pumps and AD-50 dampeners. It looks like ordinary hardware and is not: the grade, the length and the thread are chosen for a joint that is clamping an elastomer bead and being shaken several hundred times a minute.
Substituting hardware store hardware is a false economy here. Wrong grade bolts stretch, wrong length bolts bottom out before they clamp, and plated fasteners in a marine environment seize into the casting so the next rebuild starts with drilling. Keeping a few spares with the seal kit avoids all of it.
Key Features
- Genuine Yamada replacement bolt
- Fits NDP-50 Series pumps and AD-50 dampeners
- 12 per pump in the assembly that uses it
- Correct grade, length and thread for the joint
- Keeps clamping load even around elastomer sealed faces
- Direct replacement for corroded, stretched or missing hardware
Applications
- NDP-50 Series pumps and AD-50 dampeners
- Pump rebuilds and scheduled overhauls
- Replacing corroded or seized hardware
- Making up a complete set after a strip down
- Marine installations where corrosion takes fasteners first
- Industrial and transfer pump service
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 621213
- Part Type: Bolt
- Fits: NDP-50 Series pumps and AD-50 dampeners
- Quantity Used: 12 per pump
- Series Port Size: 2 in on the NDP-50 Series
- Condition: New
Frequently Asked Questions
Q: Do I need to replace all of them at once?
If several are corroded, replace the set. A mix of new and tired fasteners gives uneven clamping, and the old ones will need doing at the next service anyway.
Q: Should I use thread lubricant?
An anti seize compound on the threads is normal practice on this kind of assembly, particularly in marine service where it is what allows the joint to be opened again.
Q: What happens if one is left loose?
The clamping load is uneven, the joint weeps at that point, and the remaining fasteners carry more cyclic load than they were meant to.
Q: Can I use a standard bolt from a hardware store?
It is not advisable. Grade, length and thread are chosen for the joint, and a substitute that stretches or bottoms out changes the clamping load on a face that is sealed by an elastomer bead.
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 bolt.
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