Wire mold to 1/2" knockout

I use adhesive surface mount plastic raceways and I was wondering if there is such a thing that can convert raceways to 1/2" knockouts on boxes. I know I should probably be using 1/2" EMT but it’s expensive.

http://www.legrand.us/wiremold/raceway/steel-raceway/single-channel-raceway/500-700-small-raceway/5781-box-connector.aspx

http://www.gordonelectricsupply.com/index~text~2897863~path~product~part~2897863~ds~dept~process~search?gclid=Cj0KEQjwmIrJBRCRmJ_x7KDo-9oBEiQAuUPKMqJTRROsXhQUoltbERwUqLO9aNEEd-zn1KpO0mj635UaAlUX8P8HAQ

Plastic though… No clue - I would never use the plastic wiremold. Unless you spend alot of time mounting it, it’s falling down 6 months after you’re gone.