Abstract: A tissue culture method and a propagation method of Cathaya argyrophylla are described herein. An adventitious bud can be induced from an explant of the Cathaya argyrophylla using a suitable induction medium, with an induction rate reaching 69.22% to 73.33%. The induced adventitious bud is inoculated into a suitable proliferation medium, such that the adventitious bud can proliferate and strengthen seedlings, where the adventitious bud shows a proliferation rate reaching 46.23% to 55%. The adventitious bud after proliferation and seedling strengthening are inoculated into a suitable rooting medium to allow rooting culture, thereby obtaining a complete tissue culture seedling of the Cathaya argyrophylla. The tissue culture method is of great significance for protecting the Cathaya argyrophylla, increasing a plant quantity of the Cathaya argyrophylla, and expanding a population of the Cathaya argyrophylla to prevent extinction.

Abstract: A bit accessory for a bit has a sleeve with an accommodating cavity running through the sleeve and a limiting member with a limiting hole running through the limiting member. The sleeve includes a first stopping portion for stopping the limiting member from passing through the accommodating cavity and the limiting member includes a first hole wall portion forming a first hole wall which provides the limiting hole with a minimum hole diameter and a second hole wall portion forming a second hole wall which provides the limiting hole with a maximum hole diameter. The limiting member is at least partly accommodated in the accommodating cavity, and a direction which the limiting hole runs through the limiting member is parallel to the accommodating cavity when the limiting member is stopped by the first stopping portion.

Abstract: A screwdriver includes bits, a handle for a user to grip and a magnetic device with magnetic performance, which can be engaged with the bit to attract a fastener, so that the fastener does not easily fall off when driven by the bit. The handle is formed with a containing recess, and the magnetic device is removably contained in the containing recess.

Abstract: A bit holder includes a body having a shank at its rearward end and a socket formed at its forward end to allow a tool bit to be inserted therein, a sleeve slidably disposed on the body, a collar detachably coupled to the sleeve, and a first magnet member disposed at a forward side of the collar to magnetize a fastener and retain the fastener engaged to the tool bit. The collar defines a through-hole to allow the tool bit to pass through, a forward groove for receiving the first magnet member, and a rearward groove for coupling the sleeve. The through-hole is disposed between the forward groove and the rearward groove.

Abstract: A bit accessory for a bit has a sleeve with an accommodating cavity running through the sleeve and a limiting member with a limiting hole running through the limiting member. The sleeve includes a first stopping portion for stopping the limiting member from passing through the accommodating cavity and the limiting member includes a first hole wall portion forming a first hole wall which provides the limiting hole with a minimum hole diameter and a second hole wall portion forming a second hole wall which provides the limiting hole with a maximum hole diameter. The limiting member is at least partly accommodated in the accommodating cavity, and a direction which the limiting hole runs through the limiting member is parallel to the accommodating cavity when the limiting member is stopped by the first stopping portion.