Blackburn 40HPW AL SPLITBOLT CONN W/SP 4/0STR-4SLD

The 40HPW covers 4/0 stranded down to 4 AWG solid, which is the range printed in its description. That span lets one connector handle a service-entrance tap down to a branch conductor, so a single part number covers a lot of the splices on a job. It is sold individually, one connector per unit, so count your splices when ordering.

It is an aluminum-rated split bolt, listed as AL in the part description, and the body is copper alloy with an electro tin-plated finish. Tin plating over copper alloy is what makes it suitable for aluminum as well as copper, since it keeps dissimilar metals from sitting in direct contact. For aluminum work you still need to wire brush the conductor and apply an oxide-inhibiting compound before making the splice.

Yes, it carries UL file E9809. That matters on inspected commercial and institutional work where the AHJ wants a listed mechanical connector on the splice rather than an unlisted bolt. It is a mechanical connector, not a compression lug, so no crimp tool or die set is involved.

The W designates the connector supplied with the spacer, and the spacer ships as part of the 40HPW (the description reads W/SP). The spacer separates the two conductors inside the bolt so each one seats against the bolt body rather than against each other, which is what you want when splicing two different wire sizes or mixing solid and stranded.

Yes. A split bolt is a bare mechanical connector, so the finished splice has to be insulated to the same level as the conductor insulation, normally with rubber splicing tape covered by vinyl electrical tape, or with a molded split bolt cover sized to the connector. Budget that material into the job, since it does not come with the connector.

A split bolt such as the 40HPW is the choice when you want a re-openable, tool-light splice: a wrench makes it up, and it can be taken apart for troubleshooting or re-termination. A compression sleeve is the choice where you need a permanent, low-profile splice that fits inside a tight raceway or pull box, since a taped split bolt is bulkier. For direct-buried or submersible work, compression is the usual call. Both are mechanical versus crimp decisions, not ampacity decisions.

It handles that kind of unequal splice directly. With a range of 4/0 stranded down to 4 AWG solid and the spacer included, you can land a smaller solid grounding conductor against a much larger stranded run and keep both conductors seated properly in the bolt. Tin-plated copper alloy construction means it is rated for both copper and aluminum conductors.

Manufacturing origin is Mexico. That is the figure to quote on submittals or procurement paperwork where country of origin has to be declared, such as public-agency or federally funded electrical work.