Abstract: The invention relates to a drill bit (20) for percussive rock drilling, which comprises: —a drill head (21); —a skirt (24), which has a first end and an opposite second end, the skirt being connected to the drill head at said first end; —a recess (25) extending axially through the skirt from the second end of the skirt towards the first end thereof, the recess being provided with an internal, cylindrical female thread (26); and —an impact surface (27) at the bottom of the recess. Every cross-section of the recess (25) between the impact surface and the part of the recess where the female thread has its full thread profile has a cross-sectional area which is smaller than the cross-sectional area of a cross-section of the recess at the part of the recess where the female thread has its full thread profile.

Abstract: The invention relates to a drill bit (20) for percussive rock drilling, which comprises: —a drill head (21); —a skirt (24), which has a first end and an opposite second end, the skirt being connected to the drill head at said first end; —a recess (25) extending axially through the skirt from the second end of the skirt towards the first end thereof, the recess being provided with an internal, cylindrical female thread (26); and—an impact surface (27) at the bottom of the recess. Every cross-section of the recess (25) between the impact surface and the part of the recess where the female thread has its full thread profile has a cross-sectional area which is smaller than the cross-sectional area of a cross-section of the recess at the part of the recess where the female thread has its full thread profile.

Abstract: In a first aspect, the invention relates to a rock-drilling tool that comprises a drill rod (1) having a male thread (5) as well as a coupling sleeve having a female thread for the co-operation with the male thread of the drill rod. The male thread (5) of the drill rod may consist of a martensitic stainless steel. Axially inside the male thread (5), a waist (32) is formed in which the drill rod (1) has the smallest diameter thereof. Furthermore, an external, cylindrical guide surface (31) is positioned between the male thread (5) and the waist (32) and has the purpose of co-operating with an internal guide surface positioned between the female thread and a free end of the coupling sleeve. Furthermore, the invention relates to a drill rod as such as well as a coupling sleeve as such.

Abstract: In a first aspect, the invention relates to a rock-drilling tool that comprises a drill rod (1;1??) having a male thread (5;5?), and a coupling sleeve (7:7?) having a female thread (15:15?) for the co-operation with the male thread of the drill rod. The male thread (5;5?) of the drill rod (1;1?) may consist of a martensitic, stainless steel. The coupling sleeve consists of hardened low-alloy steel. Axially inside the male thread (5;5?), a waist (32;32?) is formed in which the drill rod (1;1?) has the smallest diameter thereof. The male thread (5;5?) has a wear volume that is larger than the wear volume of the female thread (15; 15?). Furthermore, the invention relates to a drill rod per se as well as a coupling sleeve per se.

Abstract: A drill bit intended for percussive rock drilling is formed to reduce the occurrence of cavitation during percussive drilling. The drill bit includes an integral skirt and at least one channel for transport of flush medium, such as water. The drill bit has a front face provided with buttons, which define a greatest first external diameter (D0). A recess with a female thread, such as a rope or trapezoid thread for percussive drilling, extends into the drill bit from a rear end face of the drill bit. The recess has an axial depth (L0). The external surface of the skirt includes a conical portion having an axial extension that is greater than one-eighth of the depth (L0) of the recess but smaller than the depth (L0) of the recess.

Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1–2.

Abstract: A drill bit intended for percussive rock drilling is formed to reduce the occurrence of cavitation during percussive drilling. The drill bit includes an integral skirt and at least one channel for transport of flush medium, such as water. The drill bit has a front face provided with buttons, which define a greatest first external diameter (D0). A recess with a female thread, such as a rope or trapezoid thread for percussive drilling, extends into the drill bit from a rear end face of the drill bit. The recess has an axial depth (L0). The external surface of the skirt includes a conical portion having an axial extension that is greater than one-eighth of the depth (L0) of the recess but smaller than the depth (L0) of the recess.

Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1-2.