The big ends of connecting rods and eccentrics are commonly secured using cap bolts , specifically high‑strength special connecting rod bolts (often designed as fitted, high‑tensile bolts with nuts, or as setscrews in some designs). In exam/MCQ style, the expected answer is:
→ “Special (high‑tensile) connecting rod bolts (cap bolts)”. Information gathered from public forums or data available on the internet and portrayed here.