US 11,703,074 B2
Thread-forming or self-tapping screw, in particular for use in light metal
Olaf Ambros, Biblis (DE)
Assigned to BAIER & MICHELS GMBH & CO. KG, Ober-Ramstadt (DE)
Appl. No. 15/776,020
Filed by BAIER & MICHELS GMBH & CO. KG, Ober-Ramstadt (DE)
PCT Filed Nov. 15, 2016, PCT No. PCT/EP2016/077737
§ 371(c)(1), (2) Date May 14, 2018,
PCT Pub. No. WO2017/085060, PCT Pub. Date May 26, 2017.
Claims priority of application No. 102015222889.4 (DE), filed on Nov. 19, 2015.
Prior Publication US 2018/0335068 A1, Nov. 22, 2018
Int. Cl. F16B 25/00 (2006.01)
CPC F16B 25/0047 (2013.01) [F16B 25/0021 (2013.01); F16B 25/0073 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A thread-forming or self-tapping screw, comprising: a shank provided with a thread with at least one asymmetric thread turn with a plurality of windings, wherein
(i) the thread has an external diameter (DA), a core diameter (DK) and a thread pitch (P),
(ii) the thread turn has thread flanks with a flank angle phi,
(iii) the thread flanks have a load-bearing flank and a counter-flank which abut one another at a thread bottom and at a thread tip, wherein the load-bearing flank and the counter-flank form a transition region at the thread bottom with a longitudinal extension of at least 0.01 times and at most 0.2 times the pitch P, and
(iv) a flank angle phiL of the load-bearing flank is smaller than a flank angle phiG of the counter-flank,
wherein a ratio Q1=DA/P of the external diameter (DA) in relation to the thread pitch (P) is from 3.0 to 3.6, and a ratio Q2=DK/P of the core diameter (DK) in relation to the thread pitch (P) is from 2.0 to 2.5.