ARP Derby Cover/Clutch Inspection Cover Bolt Kit for Twin Cam

(22 customer reviews)


Fits all Twin Cams


ARP Bolts Derby Cover/Clutch Inspection Cover Bolt Kit

  • These high-quality bolts will replace your low-grade factory bolts
  • 12 Point bolts in black or polished stainless to match most derby covers (will not fit recessed holes but heads can be machined down)
  • Made in the USA
  • Manufactured to Imzz Elite exact specifications

Fits all years and models of Twin Cam

(Bolt heads may not fit with CVO and some bagger model derby covers. Heads will need to be machined down to fit in recess)

Find more ARP Hardware kits for your Harley HERE.

arp hardware for harleys

What is a Black Oxide finish?

Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. It is used to add corrosion resistance, for appearance and to minimize light reflection. One of its advantages over other coatings is its minimal buildup; the blacking process creates a layer only about a micrometre thick.

Why are my new ARP bolts oily?

That oil keeps them from corroding and keeps them looking new! You’re a biker…you can’t be afraid to get your hands dirty. (If you are, trade your Harley in for  Vespa.) Hot baths of sodium hydroxide, nitrates, and nitrites (at 286 °F) are used to convert the surface of the material into magnetite (Fe3O4).  To achieve maximal corrosion resistance the black oxide must be impregnated with oil or wax. Once the process of dipping is completed the top layer of the fastener is porous and a layer of oil is applied, similar to a pickling process. The oil seeps into the material adding that extra corrosion resistance to rust.

Will they rust?

Black Oxide adds a layer of corrosion and abrasion resistance to fasteners. Like any material, black oxide treated fasteners can rust in the right environments. It will depend on if the fastener is damaged or marred, the type of metal with the black oxide treatment and environmental conditions. In high heat environments, the oil residue that stays on the fasteners will begin to turn brown. Many users find their bolts look like they rust prematurely when really, the oil is just changing colors. See the next Q&A to learn how to bring them back to looking new if they begin to show rust.

Do they require maintenance?

Like any treated, chromed or painted surface, they do require some maintenance. It’s simple and takes only a few minutes! To keep your black oxide hardware looking good and new on your bike, they must be oiled. We recommend spraying WD-40 on a rag and wiping the surface of the hardware whenever you clean your bike. Don’t wait for them to look bad before doing something. A quick swipe with WD-40 every now and then will keep them looking brand new and prevent corrosion. We use Silikroil around the shop which we prefer over WD-40. You can find it on Amazon. In hot, rainy or humid environments, they may require more frequent maintenance.

History & Background on ARP

They say that to be successful you must identify a need and satisfy it. Back the early 1970s, racing enthusiast Gary Holzapfel saw that many of his friends’ broken engines were caused by fastener failure.

At the time, there were no commercially available studs and bolts up to the challenge. So Holzapfel called upon his many years of fastener making experience for a leading aerospace subcontractor and founded ARP (Automotive Racing Products).

In the ensuing years, the firm has grown from what was literally a backyard garage workshop into a highly diversified manufacturer with seven operational entities in Southern California with a combined area in excess of 200,000 square feet. These include forging, heat-treating, machining, quality control finishing and packaging/warehousing facilities in Santa Paula and Ventura, California.

There is even a unique racing-themed restaurant at the main Santa Paula facility – called “ Hozy’s Grill” – which is open to the public.

Today, ARP’s product line contains thousands of part numbers, and has expanded to include virtually every fastener found in an engine and driveline and throughout the suspension and frame. These range from quality high performance OEM replacement parts to exotic specialty hardware for Formula 1, IndyCar, NASCAR and NHRA drag racing and marine applications.

Additional information

Weight .0875 lbs
Dimensions 1 × 1 × 1 in

Black, Polished Stainless

22 reviews for ARP Derby Cover/Clutch Inspection Cover Bolt Kit for Twin Cam

  1. Jose Mendoza (verified owner)

    Great product and service

  2. Adam (verified owner)

    High quality, perfect fit.

  3. Noah Rosa (verified owner)

    Excellent hardware

  4. Ben Barraza (verified owner)


  5. Michael C. (verified owner)

    Look great will definitely be ordering more.

  6. Bret E. (verified owner)

    Quality products, decent price

  7. Tom Dooley (verified owner)

    Perfect match!

  8. Eric D. (verified owner)

    Good quality and looks great

  9. Nick Walker (verified owner)

    Look amazing

  10. Mark R. (verified owner)

    Good stuff

  11. Craig T. (verified owner)

    Great product and service. Can’t beat ARP quality.

    Image #1 from Craig T.
  12. Lorenzo S. (verified owner)


  13. adrian (verified owner)

    Good looking

  14. Rey C. (verified owner)


  15. Daniel Coelho (verified owner)

    Perfect fit

  16. Anthony (verified owner)

    Badass and fast shipping !

  17. Anthony B. (verified owner)


  18. Kevin Ornellas (verified owner)

    Great and fast delivery

  19. Michel Stellato (verified owner)

    Very good bolts, just the ship in is to expensif, I prefer USPS option, cost more to ship then the bolt cost

  20. Roberto R. (verified owner)

    Super easy to torque don’t have to worry about stripping bolts.

  21. Doug G. (verified owner)

    Haven’t used yet look good tho .

  22. Logan S. (verified owner)

    Great quality and quick shipping

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