Abstract: A knife includes two casings for slidably supporting a knife blade. The casings includes a structure that may be easily assembled together without additional tools. The casings each includes a latch formed on one end for engaging with each other and for securing one end of the casings together. A knob is slidably engaged on one of the casings and includes a hook for engaging with the other casing and for securing the casings together. A spring may bias the hook to engage with an engaging recess of the other casing.

Abstract: A knife includes two housings having a front portion for engaging with blades. One of the housings includes a projection formed in the front portion for engaging with a depression of the other housing so as to secure the front portions of the housings together. A rod is rotatably engaged in the rear portion of one of the housings. A cap is secured to one end of the rod, and a spring biases the cap to engage with the rear ends of the housings so as to secure the rear ends of the housings together. The housings can be secured together without additional tools.

Abstract: A saw includes a handle having a channel formed in the upper portion for slidably receiving a beam. An arm is secured to one end of the beam. Two rotary members are pivotally secured to the handle and the arm for supporting a saw blade. A knob is slidably engaged in the handle and has a key for engaging with one of the rotary member and for securing the rotary member to the handle. The arm includes a stop for engaging with and for positioning the other rotary member to the arm. The beam and the arm are moved away from the handle for stretching and for securing the saw blade in place.

Abstract: An artwork gravity knife comprises a first handle body, a second handle body, a knife pushing mount, and a blade box. The first and the second handle bodies are pivoted respectively at the rear end thereof to a pivot such that they can be rotated in relation to each other. The first and the second handle bodies are provided respectively at the front end thereof with a knife pushing mount behind which the blade box is disposed. The blade box also serves to fasten securely the first and the second handle bodies. The blade in use can be replaced easily and safely with those which are kept in the built-in blade box.