Concrete screw with countersunk head W-BS/S
Concrete screw W-BS steel zinc plated type SK
CONCSCR-(W-BS/SK)-(A2K)-TX40-15-35-8X80
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- For anchorage in concrete and masonry
- Extremely flexible application thanks to up to three effective anchorage depths (size 6-10)
- Fastening can be adjusted up to two times after installation (size 6-10), for example in order to align railings or anchor plates (please refer to the installation instructions)
- Very high loads
- Very low spacing and edge distances thanks to very low expansion effect
- Very fast and easy installation and immediate load-bearing capacity
- Attractive, flush-mount installation possible
European Technical Assessment ETA-16/0043 for individual fixing point, option 1, cracked and uncracked concrete:
- Static and quasi-static action (dia. 6-10)
- Seismic action, performance category C1 (dia. 6-10) and C2 (dia. 8-10)
- Fire resistance R30, R60, R90, R120
European Technical Assessment ETA-23/0196 for anchorage in masonry
- Static and quasi-static action (dia. 5-10)
- Fire resistance R30, R60, R90, R120 (dia. 5-6)
European Technical Assessment ETA-16/0128 for anchors in a redundant non-structural system:
- Cracked and uncracked concrete, (dia. 5 and dia. 6)
- Hollow-core prestressed concrete ceilings C30/37-C50/60, (dia. 6)
- Fire resistance R30, R60, R90, R120
DIBt National technical approval/general type approval Z-21.1-2075 as bonded screw anchor for anchorage in concrete (dia. 10 ), type SK countersunk head
- Use in combination with WIT-BS injectable mortar as WIT-BS bonded screw anchor
- In reinforced and non-reinforced and cracked and uncracked concrete C20/25 to C50/60
Fire resistance rating when exposed to fire according to the standard temperature time curve in masonry (Mz, KSL, KS) and reinforced concrete, (dia. 5 and dia. 6) - expert report no 2101/173/18 - 2018
From size 8, we recommend the use of a suitable tangential impact driver for installation. The recommended maximum nominal torque must be observed. When used in masonry, the stone-specific installation data according to ETA-23/0196 must be observed.
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/normal/348px/4206421.jpg)
Railings
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/normal/348px/4206422.jpg)
Handrails
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/normal/348px/4332957.jpg)
Adjustment - subsequent aligning possible
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/37435254.jpg)
Create the drill hole
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162590.jpg)
Clean the drill hole
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162589.jpg)
Place screw
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162588.jpg)
Screw in the screw
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162587.jpg)
Considered installed when the head is close fitting
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162586.jpg)
Screw out the screw max. 2x each by max. 10 mm. Underlay. Screw in
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/12162592.jpg)
Considered installed when the head is close fitting. Lining max. 10 mm. The required embedment depth must be maintained as a minimum
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662258.jpg)
Locate the tensioning strand
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662259.jpg)
Mark the tensioning strand and locate the next one
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662260.jpg)
Mark the tensioning strands. Specify the drilling range
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662261.jpg)
Create the drill hole. Observe spacing
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662262.jpg)
Clean the drill hole
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662263.jpg)
Screw in the screw
![](https://media.wuerth.com/stmedia/wuerth/images/std.lang.all/resolutions/category/348px/3662264.jpg)
Considered installed when the head is close fitting. Observe the embedment depth/mirror thickness
Datasheets(X)
CAD data (available after login)
Anchorages in concrete, individual fixing point with approval (dia. 6-10):
In normal weight concrete C20/25 to C50/60 (cracked and uncracked concrete)
Anchors in a redundant non-structural system in concrete, with approval:
- In normal weight concrete C20/25 to C50/60 (cracked and uncracked concrete), (dia. 5 and dia. 6)
- In hollow-core prestressed concrete ceilings C30/37-C50/60, (dia. 6)
Anchorages in masonry with approval (dia. 5-10):
- In solid calcium silicate block and perforated block
- In solid block masonry brick
Specifically designed for attractive, flush-mount installation
Suitable for fastening medium to heavy loads in concrete and light to medium loads in masonry:
- Fastening of e.g. staircase railings and balcony balustrades, handrails, steel structures, wooden substructures, metal profiles etc. in in-place installation
- Fastenings subject to seismic activity in earthquake-prone areas (only concrete)
- Fastenings subject to exposure to fire
W-BS/S (galvanised steel) may only be used in dry indoor room conditions
For use in concrete < C20/25 and pressure-resistant natural stone (without approval)
Anchor size | 8 mm |
Anchor length (l) | 80 mm |
Attachment height (t fix 1) | 35 mm |
Attachment height (t fix 2) | 25 mm |
Attachment height (t fix 3) | 15 mm |
Thread diameter | 10 mm |
Nominal drill-bit diameter (d 0) | 8 mm |
Drill hole depth (h 1.1) | 55 mm |
Drill hole depth (h 1.2) | 65 mm |
Drill hole depth (h 1.3) | 75 mm |
Embedding depth (h nom1) | 45 mm |
Embedding depth (h nom2) | 55 mm |
Embedding depth (h nom3) | 65 mm |
Head diameter (d sk) | 20 mm |
Internal drive | TX40 |
Head type | Countersunk head |
Material | Steel |
Through-hole in the component to be connected (d f) | 12 mm |
Surface | Zinc plated |
Type description | W-BS type SK |
Anchor size [mm] | 6 | 8 | 10 | Performance data in concrete - fixing point according to ETA-16/0043 | ||||
Nominal length of thread engagement | hnom [mm] | |||||||
Admissible centric tension load1) on an individual anchor without the influence of the edge distance | Tensile zone (cracked concrete C20/252), s ≥ 3 hef c ≥ 1.5 hef) | Nperm. [kN] = C20/252) | ||||||
Compressive zone (non-cracked concrete C20/252), s ≥ 3 hef c ≥ 1.5 hef) | ||||||||
Admissible shear load1) on an individual anchor without the influence of the edge distance | Tensile zone (cracked concrete C20/252), c ≥ 10 hef) | Vperm. [kN] = C20/252) | ||||||
Compressive zone (non-cracked concrete C20/252), c ≥ 10 hef) | ||||||||
Permissible bending moment | Madm [Nm] | |||||||
Admissible load under seismic activity performance categories C1 and C2 see European Technical Assessment ETA-16/0043 | C1 | x | x | x | x | x | ||
C2 | x | x | ||||||
Admissible load when exposed to fire (R30, R60, R90, R120), see European Technical Assessment ETA-16/0043 |
Performance data in concrete - anchors in a redundant non-structural system according to ETA-16/0128 | ||||
Anchor size [mm] | 5 | 6 | ||
Nominal length of thread engagement | hnom [mm] | |||
Anchors in concrete in a non-structural system based on a redundant design3) | Nperm. [kN] ≥ C20/25 | |||
Admissible shear load1) on an individual anchor without the influence of the edge distance | Tensile zone (cracked concrete C20/252), c ≥ 10 hef) | Vperm. [kN] = C20/252) | ||
Compressive zone (non-cracked concrete C20/252), c ≥ 10 hef) | ||||
Permissible bending moment | Madm [Nm] | |||
Admissible load when exposed to fire (R30, R60, R90, R120), see European Technical Assessment ETA-16/0128 |
Performance data in hollow-core prestressed concrete ceilings according to ETA-16/0128 | ||||
Anchor size [mm] | 6 | |||
Mirror thickness [mm] | ≥ 25 | ≥ 30 | ≥ 35 | |
Anchors in a redundant non-structural system in hollow-core prestressed concrete ceilings5) | Fperm. [kN] | |||
1) The partial safety factors of the resistances yM regulated in the evaluation/approval and a partial safety factor of the effects of γF = 1.4 have been taken into account. For a combination of tensile and shear loads, for the influence of the edge distance and anchor groups please see the appropriate guidelines e.g. DIN EN 1992-4. 2) The concrete has normal reinforcement. Higher values are possible for higher concrete strengths. 3) The admissible loads were determined without axial influence and the influence of the edge distance. 4) Number of attachment points ≥ 3 and at least one anchor per attachment point produces a load per attachment point of Fperm ≤ 1.4 kN or number of attachment points ≥ 4 and at least one anchor per attachment point produces a load per attachment point of Fperm ≤ 2.1 kN. The admissible loads can be increased if the design shows that the requirements governing the strength and rigidity of the component to be attached remain satisfied even after the failure of an anchor in terms of the limit state of serviceability and load-bearing capacity. 5) The assembly data must be observed. |
Installation parameters in concrete | |||||||||||
Anchor size [mm] | 5 | 6 | 8 | 10 | |||||||
Nominal length of thread engagement | hnom [mm] | 351) | 351) | 40 | 55 | 45 | 55 | 65 | 55 | 75 | 85 |
Minimum axis distance | smin [mm] | 35 | 35 | 40 | 40 | 50 | 50 | ||||
Axis distance | scr,N [mm] | 81 | 81 | 93 | 132 | 105 | 129 | 156 | 129 | 180 | 204 |
Minimum edge distance | cmin [mm] | 35 | 35 | 40 | 40 | 50 | 50 | ||||
Edge distance | ccr,N [mm] | 40,5 | 40,5 | 46,5 | 66 | 52,5 | 64,5 | 78 | 64,5 | 90 | 102 |
Minimum member thickness | hmin [mm] | 80 | 80 | 80 | 80 | ||||||
Nominal drill diameter | d0 [mm] | 5 | 6 | 8 | 10 | ||||||
Diameter of cutting edges | dcut ≤ [mm] | 5,40 | 6,40 | 8,45 | 10,45 | ||||||
Drill hole depth | h1 ≥ [mm] | 40 | 40 | 45 | 60 | 55 | 65 | 75 | 65 | 85 | 95 |
Through hole in the component being connected | df ≤ [mm] | 7 | 8 | 12 | 14 | ||||||
Internal drive | TX25 | TX30 | TX40 | TX50 | |||||||
Head diameter | dsk [mm] | 12 | 13 | 20 | 22 | ||||||
Max. rated torque of tangential impact screwdriver | Timp,max [Nm] | 110 | 160 | 300 | 400 | ||||||
1) For anchors in a redundant non-structural system |
Installation parameters in pre-loaded hollow ceiling panels | ||
Anchor size [mm] | 6 | |
Minimum axis distance | smin [mm] | 100 |
Minimum edge distance | cmin [mm] | 100 |
Minimum spacing between the groups of anchors | amin [mm] | 100 |
Distance between cavities | lc ≥ [mm] | 100 |
Spacing between tensioning strands | lp ≥ [mm] | 100 |
Spacing between tensioning strands and drilled hole | ap ≥ [mm] | 50 |
Nominal drill diameter | d0 [mm] | 6 |
Through hole in the component being connected | df ≤ [mm] | 8 |
Performance data of an individual anchor in solid and perforated block masonry according to ETA-23/0196 | ||||||||||
Anchor size | Nominal length of thread engagement | Admissible tensile load | Admissible shear load | Min. edge distance | Min. spacing | Distance from joints | Max. torque for manual installation | Max. torque for installation with drill/driver | Installation using tangential impact driver | |
Solid calcium silicate block KS NF in accordance with EN 771-2:2015-11 KS 20 - 2.0 - NF - 240 x 115 x 71 mm, stone raw density ρ ≥ 2.0 kg/dm3, stone compressive strength fmean = 26 N/mm2, minimum wall thickness hmin = 240 mm | ||||||||||
Silka XL solid calcium silicate block KS 12DF in accordance with DIN EN 771-2:2015-11 KS- R (P) - 2.0 - 12DF - 498 x 175 x 148 mm, stone raw density ρ ≥ 1.8 kg/dm3, stone compressive strength fmean = 14 N/mm2, minimum wall thickness hmin = 175 mm | ||||||||||
Hollow calcium silicate block KS L, 3DF in accordance with DIN EN 771-2:2015-11 SWKV KSL 12 - 1.6 - 3DF - 240 x 175 x 113 mm, stone raw density ρ ≥ 1.5 kg/dm3, stone compressive strength fmean = 17 N/mm2, minimum wall thickness hmin = 175 mm | ||||||||||
Masonry brick Mz in accordance with DIN EN 771-1:2015-11 Mz 20 - 2.0 - NF - 240 x 115 x 75 mm, stone raw density ρ ≥ 2.1 kg/dm3, stone compressive strength fmean = 21 N/mm2, minimum wall thickness hmin = 240 mm | ||||||||||
Lightweight concrete solid block Vbl in accordance with DIN EN 771-3:2015-11 Vbl 4 - 1.0 - 2DF - 240 x 115 x 113 mm, stone raw density ρ ≥ 1.5 kg/dm3, stone compressive strength fmean = 4 N/mm2, minimum wall thickness hmin = 240 mm | ||||||||||
5 | 35 | 0,66 | 0,91 | 80 | 80 | 40 | 80 | 6 | ||
6 | 35 | 0,66 | 0,91 | 80 | 80 | 40 | 80 | 10 | 10 | |
6 | 55 | 1,17 | 2,37 | 80 | 80 | 40 | 80 | 10 | 185 | |
8 | 45 | 1,8 | 0,91 | 80 | 80 | 40 | 80 | 25 | 300 | |
8 | 65 | 1,8 | 2,14 | 80 | 80 | 40 | 80 | 25 | 300 | |
10 | 55 | 1,83 | 1,69 | 80 | 80 | 40 | 80 | 45 | 300 | |
10 | 75 | 1,91 | 2,44 | 80 | 80 | 40 | 80 | 45 | 300 | |
5 | 35 | 0,31 | 0,46 | 58 | 80 | 35 | 58 | 6 | 8 | 100 |
6 | 35 | 0,31 | 0,46 | 58 | 80 | 35 | 58 | 11 | 10 | 100 |
6 | 55 | 0,31 | 0,46 | 58 | 80 | 35 | 58 | 11 | 100 | |
8 | 45 | 0,46 | 0,46 | 58 | 80 | 35 | 58 | 27 | 200 | |
8 | 65 | 0,46 | 0,46 | 58 | 80 | 35 | 58 | 27 | 200 | |
10 | 55 | 0,63 | 0,63 | 58 | 80 | 35 | 58 | 37 | 200 | |
10 | 75 | 0,63 | 0,63 | 58 | 80 | 35 | 58 | 46 | 200 | |
5 | 35 | 0,46 | 0,6 | 80 | 80 | 35 | 80 | 2 | 4 | |
6 | 35 | 0,46 | 0,6 | 80 | 80 | 35 | 80 | 3 | 9 | |
6 | 55 | 0,46 | 0,6 | 80 | 80 | 35 | 80 | 3 | 9 | |
8 | 45 | 0,66 | 0,6 | 80 | 80 | 35 | 80 | 16 | 14 | |
8 | 65 | 0,66 | 0,6 | 80 | 80 | 35 | 80 | 16 | 14 | |
10 | 55 | 0,86 | 0,6 | 80 | 80 | 35 | 80 | 23 | 185 | |
10 | 75 | 0,91 | 0,77 | 80 | 80 | 35 | 80 | 23 | 185 | |
8 | 65 | 0,17 | 0,66 | 80 | 80 | 35 | 80 | 6 | 10 | |
10 | 75 | 0,37 | 0,91 | 80 | 80 | 35 | 80 | 5 | 14 | |
hnom | Nadm | Vadm | cmin | smin, || = smin, ⊥ | cj ⊥ ≥ | cj || ≥ | Tinst≤ | Tinst≤ | Timp,max | |
[mm] | [mm] | [kN] | [kN] | [mm] | [mm] | [mm] | [mm] | [Nm] | [Nm] | [Nm] |
5 | 35 | 1 | 0,94 | 80 | 80 | 35 | 80 | 6 | 185 | |
6 | 35 | 0,89 | 0,94 | 80 | 80 | 35 | 80 | 11 | 10 | 185 |
6 | 55 | 1,4 | 0,94 | 80 | 80 | 35 | 80 | 11 | 185 | |
8 | 45 | 1,17 | 0,94 | 80 | 80 | 35 | 80 | 27 | 300 | |
8 | 65 | 1,23 | 0,94 | 80 | 80 | 35 | 80 | 23 | 300 | |
10 | 55 | 1,06 | 0,94 | 80 | 80 | 35 | 80 | 34 | 300 | |
10 | 75 | 1,29 | 0,94 | 80 | 80 | 35 | 80 | 146 | 300 | |
Notes: For further details on compressive strength, spacing, edge distances and installation positions, please refer to ETA-23/0196 To determine the admissible load, the partial safety factor from ETA γM=2.5 was taken into account on the resistance side and a partial safety factor γF=1.4 on the impact side. The specified values apply to an individual anchor in masonry with fvko: 0.15 [N/mm²] and σd: 0.2 [N/mm²]. For combinations of tensile and shear loads, bending torques or reduced spacing and edge distances, please see ETA-23/0196. Documentation for block removal must also be provided. |
General installation parameters in masonry: | ||||||||||
Anchor size | Diameter | 5 | 6 | 8 | 10 | |||||
Nominal length of thread engagement | hnom | hnom1 | hnom1 | hnom2 | hnom1 | hnom2 | hnom1 | hnom2 | ||
[mm] | 35 | 35 | 55 | 45 | 65 | 55 | 75 | |||
Nominal drill diameter | d0 | [mm] | 5 | 6 | 8 | 10 | ||||
Diameter of cutting edges | dcut ≤ | [mm] | 5,4 | 6,4 | 8,45 | 10,45 | ||||
Drill hole depth | h0 ≥ | [mm] | 55 | 55 | 75 | 65 | 85 | 75 | 95 | |
Through hole in the fixture | df ≤ | [mm] | 7 | 8 | 12 | 14 |