ECN Forum Forums General Topics of the Trade General Discussion Area Cutler Hammer Add a Lug

THESE are a little bit pricey and require a crimper, but will suit your need.
I've had troubles with finding field installable modifications to C-H bolt in panels in the past (although the shop I worked at was right next door to the Mira Loma facility, and I could just walk across the parking lot).

C-H is absolutely great in this respect with larger switchgear, though.