PANEL FIXING SCREW

PROBLEM TO BE SOLVED: To simplify a fixing work without spoiling an appearance in a fixed state of a panel.SOLUTION: When a panel fixing screw 10 is screwed into a panel 50, the panel 50 is cut by a cutting part 18 provided on an opposite surface 14a to the panel of a head part 14, and a counter boring part 52 is formed. The panel 50 is fixed in a state that the head 14 is sunk in the counter boring part 52. Due to that the head part 14 is spread in parallel to an orthogonal surface to a shaft center of a shank 12, and has a disc shape thinner than a thickness of the panel 50, the head part 14 is entirely sunk into the counter boring part 52. Cutting chips 50a generated by cutting the panel 50 by the cutting part 18 are stored in a storage part 20 between the opposite surface 14a of the panel of the head part 14, and a seating face 52a (see figure 3) of the counter boring part 52. Even when part of the cutting chips 50a extrude from the storage part, the cutting chips 50a are efficiently cut by receiving shearing action by a peripheral wall connected to an outer peripheral edge 52b of the counter boring part 52 and a peripheral edge part 14c of the head part 14, and is separated from the panel 50.SELECTED DRAWING: Figure 3 【課題】パネルの固定状態での見栄えを損なうことなく固定作業の簡素化を図る。【解決手段】パネル固定用ねじ１０がパネル５０にねじ込まれる際に、頭部１４のパネルとの対向面１４ａに設けられた切削部１８によってパネル５０が切削され、座ぐり５２が形成される。座ぐり５２内に頭部１４が没入した状態で、パネル５０が固定される。しかも、頭部１４が、軸部１２の軸心との直交面と平行に広がりパネル５０の厚みよりも薄い円盤状をなしていることから、座ぐり５２内に頭部１４が全て没入する。切削部１８によりパネル５０が切削されることで生じる切削くず５０ａは、頭部１４のパネルとの対向面１４ａと、座ぐり５２の座面５２ａ（図３参照）との間の収容部２０に収容される。切削くず５０ａの一部が収容部からはみ出たとしても、その切削くず５０ａは、座ぐり５２の外周縁５２ｂにつながる周壁と、頭部１４の周縁部１４ｃとによるせん断作用を受けて効率的に切断され、パネル５０から分離される。【選択図】図３