The market taxonomy of Boron‑Free Metalworking Fluids distinguishes four principal Types: water‑based, oil‑based, synthetic and semi‑synthetic formulations. Water‑based fluids, further divided into soluble concentrates, emulsifiable concentrates and ready‑to‑use solutions, dominate the segment due to their low toxicity and easy disposal, collectively representing close to 55 % of market volume. Oil‑based fluids, comprising mineral‑oil and vegetable‑oil bases, are preferred for high‑load turning and deep‑hole drilling, contributing about 25 % as they provide superior film strength. Synthetic fluids, built on ester or glycol backbones, capture roughly 12 % of the market; their thermal stability and biodegradability justify premium pricing in aerospace and medical device manufacturing. Semi‑synthetic blends, which combine water and oil phases, occupy the remaining 8 %, offering a compromise between cooling efficiency and lubricity. Each type’s share is driven by process‑specific performance criteria, regulatory constraints, and total cost of ownership, shaping the overall market size.