Are chino and drill the same fabric?

They are very close. Both are warp-faced cotton twills. Drill is the broader, stouter workwear category, while chino is a finer, smoother, more tightly finished twill originally made for military trousers. A chino is, in effect, a refined drill.

Yes. Chino is a warp-faced cotton twill, which is why it has a faint diagonal wale and the strength and crease-holding that suit it to trousers.

Why is it called chino?

The name traces to the cotton twill trousers adopted by the US military, with cloth associated with Chinese sources, so the trousers were nicknamed chinos, Spanish-influenced slang that stuck to the cloth.

Side by side

Chino vs Drill

Chino and drill are close relatives, both strong cotton twills with a diagonal wale, and the line between them blurs. Drill is the broader category: a stout warp-faced twill used for workwear, uniforms, and upholstery. Chino is a finer, smoother, more tightly combed version of that twill, originally a military trouser cloth, calmed down and dressed up into the casual trouser the word now names.

Chino

No. 050

steep cotton twill · first documented mid-1800s

Drill

No. 051

stout 3/1 twill · first documented 1700s

The differences

Aspect	Chino	Drill
Weave	A fine warp-faced cotton twill, smooth-finished.	A stout warp-faced cotton twill, often heavier.
Hand	Smoother, finer, lighter; a touch dressy.	Sturdier and more utilitarian.
History	From military trousers (the word came via Chinese cloth for the US Army).	A long-standing workwear and uniform cloth.
Best for	Casual trousers, smart-casual wear.	Workwear, uniforms, bags, upholstery.

Which to choose

Chino is essentially a refined drill: the same warp-faced cotton twill, made finer and smoother for trousers. If the cloth is fine, smooth, and trouser-weight, call it chino; if it is stouter and built for hard use, call it drill.

Common questions

Are chino and drill the same fabric?: They are very close. Both are warp-faced cotton twills. Drill is the broader, stouter workwear category, while chino is a finer, smoother, more tightly finished twill originally made for military trousers. A chino is, in effect, a refined drill.
Is chino a twill?: Yes. Chino is a warp-faced cotton twill, which is why it has a faint diagonal wale and the strength and crease-holding that suit it to trousers.
Why is it called chino?: The name traces to the cotton twill trousers adopted by the US military, with cloth associated with Chinese sources, so the trousers were nicknamed chinos, Spanish-influenced slang that stuck to the cloth.

Full entry: Chino Full entry: Drill

Sources & References

1.Chino cloth, Wikipedia
2.chino, Online Etymology Dictionary
3.Drill (fabric), Wikipedia
4.Twill, Wikipedia