Original Fein cylinder‑head screw — part no. 43035009044. Precision cylindrical‑head screw, size M4 × 20 mm, the exact fastening screw specified in Fein parts diagrams for several metal‑working and drilling/mortising machines.

Why this part matters: this is the genuine Fein mounting screw used in internal assemblies (listed as "cylinder head screw" ) — the same M4×20 specification you’ll find on Fein exploded parts lists, so it restores the original fit and alignment without modifying the tool.

Example Fein models this part is shown for (check your machine’s 11‑digit type number against these listings):

- KBM 32 Q.

- RSG 1500 B (and related RSG 1500 variants).

- RDG 18‑3a.

- KBU 110‑4 M.

- JCM 125 Q

Short and useful: if a stripped, missing or damaged M4×20 cylinder‑head screw is preventing reassembly or causing play in a Fein unit, replacing it with the original Fein part 43035009044 returns the exact thread, head profile and length the manufacturer specified.