Burks 21182 Stainless Steel Impeller Lock Screw 1/4-28 by 1/2 in
This is the impeller lock screw Burks lists as part 21182 in stainless steel, 1/4-28 by 1/2 in hex head, on WA6 and GA series pumps. Material and thread specification are both chosen for the job, which is why the part carries its own number rather than being left to the fitter.
Fasteners in a wet end corrode, stretch and gall. A stud that has been through several heat cycles in a corrosive liquid has usually lost some section, and a stretched fastener no longer delivers its clamping load at the specified torque. Galled threads are worse, because they seize partway and give a false torque reading while the joint underneath is still loose.
Follow the Burks torque figures and the tightening sequence rather than working by feel. This part is 1/4-28 by 1/2 in hex head, for WA6 and GA series pumps. Even clamping is what makes a gasket seal, and over-tightening a fastener in a cast housing is a quick way to pull a thread out.
Key Features
- Genuine Burks replacement impeller lock screw
- Stainless steel as originally specified
- 1/4-28 by 1/2 in hex head thread and length
- Listed for WA6 and GA series pumps
- Chosen for corrosion resistance in the pumped liquid
- Holds its clamping load at the specified torque
Applications
- Burks WA6 and GA series pump rebuilds
- Replacing corroded or stretched original fasteners
- Reassembly after an impeller or casing change
- Recovery after a fastener seized or snapped on removal
- Restocking a planned maintenance spares kit
- Industrial, marine and dockside installations
Specifications
- Brand: Burks
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 21182
- Part Type: Impeller Lock Screw
- Material: Stainless steel
- Size: 1/4-28 by 1/2 in hex head
- Fits: Burks WA6 and GA series pumps
- Condition: New
Frequently Asked Questions
Q: How do I confirm this is the right one?
Compare thread size, pitch, length and head form against the part you removed, and check it against the parts list for your pump model. Similar is not the same when the fastener is holding a rotating assembly.
Q: Can I use a standard fastener from stock instead?
It will thread in, and that is the problem. The original is specified for corrosion resistance in the liquid the pump handles as well as for strength, and a commercial substitute tends to seize in place and make the next service far harder.
Q: What torque should I use?
The figure in the Burks service literature for that joint. Working by feel is how threads get pulled out of cast housings and how gaskets get pinched, and a torque wrench costs less than either repair.
Q: Should these be replaced as a set?
On a multi-fastener joint, yes. They have all done the same hours in the same liquid, and one tired fastener in a set gives uneven clamping, which is a common cause of a joint that weeps after reassembly.
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 impeller lock screw before you order.
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