When crimping hose fittings, if the crimp dimension is excessive, the inner rubber layer and the braided steel wires of the hose can be crushed, leading to oil leakage. Conversely, if the dimension is insufficient, excessive pressure during operation may also cause leaks; in extreme cases, over‑pressurization can even force the fitting to detach entirely, potentially injuring personnel. Therefore, it is essential to maintain proper crimp dimensions, using the degree of contraction at the inner bore of the fitting’s tail as the reference. For standard‑compliant fittings, the recommended compression is 0.1–0.4 mm; for ordinary fittings, it is 0.1–1 mm. Additionally, due to variations among hose manufacturers and fitting sleeve producers, actual dimensions may differ.