Bulkheads
"Bulkhead Plates" (or bulkheads) fit inside airframe tubing while "Coupler Bulkhead Plates" fit inside couplers.
You can browse this entire category, or limit your selection to bulkheads or coupler bulkheads.
2.6" Coupler Bulk plate (B)
2.6" Coupler bulkplate fits inside Rocketarium 2.6 Coupler for Bays 1/4" plywood. Bulkhead OD 2.42" See next item for other 2.6 Coupler Bulkheads
3" Coupler Bulk plate (P)
3" Coupler bulkplate fits inside 3" Phenolic or Blue Tube Coupler. 1/4" plywood. Dimensions: - 2.858", 1/4", 16.4g
4" Coupler Bulk plate
4" Coupler bulkplate fits inside 4" Coupler. 1/4" plywood. For thick wall couplers, such as Rocketarium or Madcow kraft. (bulkhead OD 3.7") See next...
4" Coupler Bulk plate (P)
4" Coupler bulkplate fits inside 4" Coupler. 1/4" plywood. For thick wall couplers, such as PML Quantum and Phenolic Couplers. (bulkhead OD 3.74")...
4" Coupler Bulk plate (A)
4" Coupler bulkplate fits inside couplers with ID 3.8". 1/4" plywood. For paper/kraft couplers, such as made by LOC, Aerotech. (OD 3.8") See previous...