In short - not really, mainly due to the fact that they were generally not used on the battlefield. If peasants were using farming implements as a makeshift weapons (usually in some kind of uprising or emergency mobilisation) they were converting regular tools for lethal use, but even then this was seen as weapons of the last resort, when absolutely nothing else was available. It should be noted that until fairly recent era (in some less developed areas of Europe even until mid-20th century) most of the farming implements were hand-made of wood, quite often by the farmers themselves and thus a far cry from modern implements usually made of high-quality tool steel. Pitchforks, flails, rakes or bills were essentially wooden sticks or forged branches that were debarked, smoothed, hardened with fire and soaked in oil to prevent excessive drying and to protect them from humidity. So, they made very durable and lightweight tools but definitely poor weapons, even against people wearing modicum of armour, not to mention any well-equipped enemy. Scythes and sickles were made of metal, but the blades of the former were way to long and thin to pose much of a threat (they resurged in XVII century however, what could have been caused by the general resignation from personal armour among infantry and sometimes also cavalry, but they were still limited to peasant uprisings and considered a weapon of last resort as armies were no longer dependent on feudal levies and thus did not require peasants to possess actual weapons). European sickles were also hard to use as a serious weapon due to their shape and size - any form of long knife would be way more useful on a battlefield.

Now, from what we know about improvised weapons I mentioned above, they were either weapons made from scratch, usually by combining a metal spike or weight to a simple pole or club, making a makeshift spiked mace or spear (with Flemish goedendag or plançon being good examples of such weapons, but it should be noted that these specific arms were actually used by burghers rather than peasants) or they were similarly converted farming implements e.g. by embedding nails or weights in the head of the flails. These were still rather rare, as even the well-organized armies composed mainly of peasants (Hussite troops being a good, albeit very late Medieval example) preferred simple polearms with an ubiquitous spear of pike being the most prominent - its manufacture was no more complex than that of any weapon mentioned above while its usefulness and versatility was usually greater. If the peasant or even a soldier was forced to use a tool for combat, his first pick would be not a farming implement but rather an axe. It has been and still is an essential and ubiquitous tool, it was readily available in almost every homestead and its usefulness in combat is undisputed. But in most cases, peasants levies were formed from freeholders who were obliged to be adequately equipped (or their landowners were tasked with equipping adequate number of soldiers). For example, in the Assize of Arms issued by Henry II in 1181, each freeholder subjected to potential conscription in case of war was required to have a mail shirt, helmet and a lance and the Statute of Arms from 1252 states that the poorest freeholders (with land worth 40 shillings or less) need to have at least a guisarme and a falchion, although the latter is disputed as the Latin term used (falca) may have different meanings. It is worth noting that the rebels who took part in Wat Tyler's uprising in 1381 were described as being armed with sticks (possibly hand-made maces), axes, old swords and bows, i.e. not unlike the regular infantry on a battlefield.