Project Kics Kyokugen Heptagon 42mm Closed-End Lug Nuts | M12 x 1.5 (AE86 Corolla / AW11 MR2 / AE92 Corolla)

Project Kics Kyokugen Heptagon 42mm Closed-End Lug Nut Set

For 1983–1987 Toyota Corolla AE86, 1984–1989 Toyota MR2 AW11, and 1987–1991 Toyota Corolla AE92 coupe equipped with M12 × 1.5 right-hand studs and aftermarket 60° conical-seat wheels.

Overview

The Project Kics Kyokugen Heptagon 42mm Closed-End Lug Nut Set is a 20-piece wheel-hardware set for the 1983–1987 Toyota Corolla AE86, 1984–1989 MR2 AW11 and 1987–1991 Corolla AE92 coupe applications. Fitment depends on M12 × 1.5 right-hand studs, aftermarket 60° conical wheel seats, adequate thread engagement and nut/adapter clearance, not the chassis name alone.

Each nut uses Project Kics' seven-sided heptagon profile and requires the supplied matching adapter for installation and removal. The 42 mm closed-end design covers the end of the wheel stud while providing an extended tuner-style profile.

The set contains 20 lug nuts plus the dedicated heptagon adapter. Corolla AE86, MR2 AW11 and Corolla AE92 applications use four-lug wheel configurations requiring 16 lug nuts per vehicle, leaving four spare nuts.

Key Features

• M12 x 1.5 thread size for Toyota Corolla AE86 Trueno / Levin / GT-S / SR5, MR2 AW11 and Corolla AE92 wheel studs
• Forged SCM435 chromoly-steel construction
• 42 mm overall length
• Seven-sided heptagon profile requiring the supplied dedicated adapter
• 60° conical / tapered seat for appropriate aftermarket wheels
• Closed-end construction covers the exposed end of the wheel stud
• Compact tuner-style profile suitable for many aftermarket wheel designs
• Black finish
• 20-piece set provides four spare lug nuts on a standard four-lug Corolla AE86, MR2 AW11 or Corolla AE92
• Dedicated heptagon installation/removal adapter included

Heptagon Design & Wheel Compatibility

The Kyokugen design replaces a conventional six-sided hex profile with a seven-sided heptagon shape. A normal hex socket cannot properly engage the nut, so the supplied Project Kics adapter is required for installation and removal.

The heptagon profile adds a level of removal deterrence compared with conventional hex lug nuts, although it should not be considered a dedicated locking-lug system.

Wheel-seat design is critical. These lug nuts use a 60° conical seat and are intended for aftermarket wheels designed for tapered-seat lug hardware. Matching the M12 x 1.5 thread alone does not guarantee proper wheel compatibility.

Vehicle Fitment

Toyota Corolla — AE86

• 1983–1987: Trueno (JDM) / 4A-GE
• 1983–1987: Levin (JDM) / 4A-GE
• 1985–1987: GT-S (U.S.-Market) / 4A-GE / Manual
• 1984–1987: SR5 (U.S.-Market) / 4A-C

Toyota MR2 — AW11 / MK1

• 1984–1989: JDM / 4A-GE
• 1985–1989: U.S.-Market / 4A-GE
• 1986–1989: JDM Supercharged / 4A-GZE
• 1988–1989: U.S.-Market Supercharged / 4A-GZE

Toyota Corolla — AE92 Coupe

• 1987–1991: JDM Corolla Levin / Sprinter Trueno coupes / 4A-GE or 4A-GZE
• 1988–1989: U.S.-Market SR5 coupe / 4A-F
• 1988–1991: GT-S coupe (U.S.-Market) / 4A-GE / Manual
• 1990–1991: SR5 coupe (U.S.-Market) / 4A-FE

All applications require M12 × 1.5 right-hand wheel studs and aftermarket wheels with matching 60° conical lug seats.

Fitment Notes

• For aftermarket wheels with a matching 60° conical seat and M12 × 1.5 right-hand studs only. This is not blanket original-wheel fitment.
• Excludes flat/washer, mag/shank, ball/radius, inverted and other nonmatching seats or changed stud threads.
• The nut seat must contact the wheel fully, with adequate thread engagement and clearance for the nut and supplied adapter. Spacers, changed studs or hub conversions can alter these requirements.
• Closed-end nuts require sufficient internal stud clearance; the stud must not bottom out before the wheel is clamped.
• The supplied heptagon adapter is required; its 24 mm outside diameter must clear the wheel recess.
• AE86 uses a 4 × 114.3 mm wheel bolt pattern; AW11 uses 4 × 100 mm. Bolt pattern does not determine stud-thread or seat compatibility.
• AE86, AW11 and AE92 four-lug applications require 16 nuts, leaving four spares.

Product Specifications

Brand: Project Kics
Series: Kyokugen Heptagon
Product Type: Wheel Lug Nut Set
Thread Size: M12 x 1.5
Seat Type: 60° Conical / Tapered
Overall Length: 42 mm
Material: Forged SCM435 Chromoly Steel
Design: Seven-Sided Heptagon
End Type: Closed End
Color: Black
Quantity: 20 Lug Nuts
Installation Tool: Dedicated Heptagon Adapter Included
Wheel Application: Aftermarket Wheels with 60° Conical Lug Seats
Vehicle Lug Configuration: Four-Lug Applications
Lug Nuts Required per Four-Lug Vehicle: 16

Which Lug Nut Set Should You Buy?

Project Kics R40 — Best for extended studs and less rubbing against the wheel seat

Choose R40 if you need room for extended studs or want less rotational rubbing against the wheel seat: its open end leaves no cap for the stud to bottom against, while the floating taper collar stays seated as the nut turns. The 44 mm body has an open end rather than a cap; the wheel seat must support the full collar, and this set includes separate locking nuts.

RAYS L31 — Best for a shorter, understated look with separate wheel locks

Choose RAYS L31 if you want a more compact, closed-end appearance with conventional hex nuts and separate wheel locks. Its 31 mm standard nuts are shorter than the other two choices, but the closed ends require enough internal room for your studs; the locks use their own key.

Project Kics Kyokugen — Best for a taller, capped look with matching nut profiles

Choose Kyokugen if you prefer a taller closed-end appearance and the same seven-sided profile on every nut. The 42 mm nuts require the supplied heptagon adapter for every wheel nut; this is not a separate locking-nut system, and the closed ends still need adequate internal stud clearance.

All three require M12 × 1.5 right-hand studs, matching aftermarket 60° conical wheel seats, adequate thread engagement and room for the nuts and their tools. Overall nut length is not usable internal stud clearance.

Our Recommendation: Choose RAYS L31 for a compact capped appearance with separate locks, R40 when extended-stud clearance or reduced wheel-seat rubbing matters more, or Kyokugen for a taller capped look if you are comfortable relying on its dedicated adapter. The best choice is the one that clears your actual wheels and studs.

What's Included

• (20) Project Kics Kyokugen Heptagon 42 mm Closed-End Lug Nuts
• (1) Dedicated Heptagon Adapter