A machine for acquiring data for measuring the twist and concavity of agricultural discs, designed for measuring the twist and concavity of agricultural discs, with a frame that supports the various elements in the machine, comprising: - a rotational mounting bracket, upon which an agricultural disc is supported and held; - a hold-down plate that can rotate freely, arranged above the mounting bracket, both elements being located opposite one another (3,13) in the same vertical direction; - a linear actuator, which displaces vertically in a downwards direction towards the hold-down plate, where, when the hold-down plate is in a lower end position, the same presses and buts against a central area of the agricultural disc placed on the mounting bracket, whilst, when said hold-down plate is in other upper positions, the same is distanced from the agricultural disc; - a laser measurement device, arranged above the agricultural disc to be measured, in turn coupled to a linear guide, arranged in a direction perpendicular to the vertical direction in which the hold-down plate travels, which coincides with the vertical direction around which the mounting bracket rotates, characterised in that: - the hold-down plate forms part of a rotational head-piece fixed to a rod of a vertical cylinder by means of a female sleeve, the vertical cylinder constituting the linear actuator used to displace the hold-down plate vertically; - the rotational head-piece comprises a lower fixation sleeve upon which the hold-down plate is supported, an upper fixation sleeve coupled to the female sleeve and an intermediate axial load ball bearing interspersed between both fixation sleeves (17,18); - the intermediate ball bearing is housed in a hollow delimited by an end annular recess in the female sleeve and by circumferential portions (17a, 18a) of both fixation sleeves: the upper and lower fixation sleeves; and - the two fixation sleeves (17, 18) are joined by screws. - a rotational mounting bracket, upon which an agricultural disc is supported and held; - a hold-down plate that can rotate freely, arranged above the mounting bracket, both elements being located opposite one another (3,13) in the same vertical direction; - a linear actuator, which displaces vertically in a downwards direction towards the hold-down plate, where, when the hold-down plate is in a lower end position, the same presses and buts against a central area of the agricultural disc placed on the mounting bracket, whilst, when said hold-down plate is in other upper positions, the same is distanced from the agricultural disc; - a laser measurement device, arranged above the agricultural disc to be measured, in turn coupled to a linear guide, arranged in a direction perpendicular to the vertical direction in which the hold-down plate travels, which coincides with the vertical direction around which the mounting bracket rotates, characterised in that: - the hold-down plate forms part of a rotational head-piece fixed to a rod of a vertical cylinder by means of a female sleeve, the vertical cylinder constituting the linear actuator used to displace the hold-down plate vertically; - the rotational head-piece comprises a lower fixation sleeve upon which the hold-down plate is supported, an upper fixation sleeve coupled to the female sleeve and an intermediate axial load ball bearing interspersed between both fixation sleeves (17,18); - the intermediate ball bearing is housed in a hollow delimited by an end annular recess in the female sleeve and by circumferential portions (17a, 18a) of both fixation sleeves: the upper and lower fixation sleeves; and - the two fixation sleeves (17, 18) are joined by screws.