Detroit Steel Treating welcomes Honhart customers

Honhart Mid-Nite black logo

Detroit Steel Treating (DST) is proud to be the future operator of Honhart Company's black oxiding line. DST will begin relocating the line from Troy to Pontiac at the beginning of October and expect to have the line operational in Q1 2021. In the meantime, Detroit Steel Treating is ready and able to process your black oxide work in their current line. We are committed to providing superior black oxiding quality that Honhart Mid-Nite Black Company’s customers have come to expect since 1945. In addition to black oxide coating, we offer heat treating, shot blasting, and straightening, as well as pick-up and delivery service to select areas.

To complement our current black oxide capability, we expect to have the newly acquired equipment fully operational in Q1 2021

The “Mid-Nite Black” process

Valve spring image

Detroit Steel Treating performs only “hot” black oxiding, which is a conversion coating formed when parts are immersed in an alkaline aqueous salt solution operated at approximately 285 °F. The reaction between the iron in the steel and the hot oxide bath produces a magnetite (Fe³O⁴) on the surface of the part.

The five basic steps for the black oxide conversion coating are: clean; rinse; immersion in hot alkaline salt solution; rinse; and supplementary coating (after finish).

The supplementary coating (after finish) dicates the final appearance. Our standard finish is regular “wet” oil, but we do offer a “dry-touch” oil for an additional charge. The wet oil will generally have a glossy finish, whereas the dry-touch oil will have less sheen.

Black oxided fastenersBlack oxided head bolts

Please specify the following when sending parts to DST for black oxiding

  • steel type
  • part number(s) and/or description of each part
  • the quantity of each part
  • any special handling, e.g. mention of delicate areas or surfaces
  • type of finishing oil
  • type of certification (if any) needed (AMS 2485, GMW 17156, ISO 11408)

Key points to remember

  • Black oxide is a conversion coating of the base metal. This means no metal is removed or deposited, and there are no dimensional changes.
  • The steel type, including whether or not it has been heat treated, will result in differing degrees of how “black” your parts will look after processing.