Hammond HP350 3.5 in Conduit Steel Hole Plug, ANSI 61 Gray

The Hammond HP350 is an ANSI 61 gray steel hole plug for 3.5" conduit openings. It closes an unused conduit opening or knockout hole with a maximum hole diameter of 4.12 in (105 mm), making it a practical accessory for electricians, panel shops and facilities teams who resize or reroute conduit on an existing enclosure.

Made of steel and finished in ANSI 61 gray, the HP350 is one of two colour options for this size; the same size in RAL7035 light gray is part number HP350LG. An oil resistant gasket seals the plug face, and a 10-24 x 0.55" threaded stud with a plated wing nut clamps it in place.

The plug diameter is 4.62 in (117 mm), and the part drawing shows a 4.63 in overall diameter along with 0.23 in and 0.79 in dimensions in its side and bottom views. Shipping weight is 1 lbs (0.45 kg), and it is listed in the Steel table of the HP Series ordering chart.

Steel HP Series hole plugs are a Recognized component UR & cUR for Type 1, 3, 3R, 4, 12 and 13, and are designed to seal against dust, oil and water. The HP350 is listed as REACH and RoHS compliant, with UPC 623980410814.