Flails

Flails are tools and/or weapons that can be used as agricultural tools for farming or weapons in a fight.

Overview of flail types

Image	Item	Blunt	Edge	Point	Attack Bonus	Defense Bonus	One-handed penalty	Weight	Value	Val/lbs.	Comments
	Grainflail	6	0	0	3	2	30	2 lbs.	16	8	Two-handed, can be crafted. An agricultural tool for threshing and improvised weapon.
	Small Flail	2	0	0	3	1	0	1 lbs.	8	8	One-handed, useful as a small weapon in particular.

The most common flail is the Grainflail. It can be crafted with the "shift+M" key command and then selecting the "Utility articles" submenu from the crafting menu.

The Small Flail is a smaller, lighter version, also usable as a close combat weapon.

The rarer Ball & Chain and Warflail are specialiased as proper, purpose-built weapons, rather than tools also usable as weapons.

URW Game Encyclopedia description

The official URW in-game encyclopedia (accessed by the F1 key) describes flails (in general) thusly:

Flails are threshing tools for separating the usable parts from the rest of the harvested plant, but flails can be also used as a weapon. Threshing itself is one of the actions covered by agriculture skill.