Shim material is used for gap filling in aircraft. Usually, the structure of a shim is multiple layers of bonded foil sheets of material, or half solid, with a thicker sheet backed with multiple layers of foil sheets.
Aluminium Shims are those most commonly used in aircraft. Boeing aircraft use BAC1534 (F) part numbers, which can be either fully laminated with 0.002” or 0.003” laminations of 1100 aluminium foil, or half solid using 2024 T3 Clad material for the sold half. The MIL/AMS-DTL-22499 specifications cover similar shim materials, with composition 1 covering aluminium shims.
Stainless Steel Shims also find use within aircraft for gap filling. The BAC1534 (C) spec covers stainless steel shims that can be fully laminated, with 0.002” or 0.003” laminations of 302/304 steel or half solid with 304 stainless steel. Suppose the MIL/AMS-DTL-22499 specification asks for Composition 3. In that case, a stainless steel shim is required, with Type 1 fully laminated and type 2 half solid.
Polymide Shims are becoming more common in aircraft with the move toward composite materials. BAC1535 parts are made from laminated phenolic linen sheets. We work closely with key suppliers to offer our customers a full range of shim materials.
Our stock range includes the finest quality alloys selected explicitly to support the MRO sector. We recognise that an aircraft out of service is a huge cost; therefore, we stock the right products to suit your engineering requirements.