Family-run brickworks that has been producing facing, paving and speciality clinker bricks as well as thin brick slips from Bockhorn clay since 1906.
Bockhorner Klinkerziegelei Uhlhorn GmbH & Co. KG
26345 Bockhorn-GrabstedeNew on Amplifa
The brickworks since 1906
Bockhorner Klinkerziegelei Uhlhorn GmbH & Co. KG has been producing facing and paving clinker bricks as well as speciality clinker bricks and thin brick slips at its Bockhorn-Grabstede site since 1906. Production is based on the regionally sourced Bockhorn clay from the Friesische Wehde, which is prepared in the soaking house, mixed in a double-shaft mixer, shaped in a stiff-mud extruder, cut to size by the harp cutter, dried for around 72 hours in the drying chamber and fired at temperatures of up to approx. 1200 °C in two tunnel kilns. The product range comprises facing clinker bricks in red, variegated, brown-violet and anthracite with various surfaces (smooth, hand-scraped, profiled, retro), paving clinker bricks in formats that can be laid flat or on edge, unperforated speciality bricks including manually smoothed corner clinker bricks, and Eco thin brick slips based on the principle of “one brick, two slips”. Customers include the building and architecture sector, facade construction, road and path construction as well as civil engineering; a reference project is among others the Wilhelmshaven Town Hall. The products comply with DIN EN 771-1 (dimensional tolerances T2) and DIN EN 1344 and DIN 18503 respectively, and are subject to continuous in-house production control as well as external surveillance by Güteschutz Ziegel. The factory premises feature an indoor and outdoor exhibition as well as a permanent historical exhibition.
- Site
- Bockhorn-Grabstede
- Processes
- Clinker production (extrusion/shaping, drying, firing in tunnel kiln), Manufacture of facing clinker bricks, Manufacture of paving clinker bricks, Manufacture of speciality bricks/speciality clinker bricks (incl. manually smoothed corner clinker, Manufacture of thin brick slips (Eco thin brick slips – one brick, two slips), Drying in drying chamber, Firing at high temperatures of up to approx. 1200 °C, Quality control / in-house production control (laboratory)
- Materials
- Bockhorn clay, Clay (fired clinker), Bockhorn Clay, Fired Clay (Clinker), Dimensional Tolerance Class T2 (DIN EN 771-1)
- Certificates
- DIN EN ISO 50001:2018, DIN EN ISO 50001:2018 (Energy Management), DIN EN 771-1 (facing clinker bricks), DIN EN 1344 / DIN 18503 (paving clinker bricks), External surveillance by Güteschutz Ziegel e.V.
- Founded
- 1906
- Industries
- Building / Architecture, Facade construction (facing clinker bricks), Road and path construction / Landscaping (paving clinker bricks), Civil engineering
- 01
Clay extraction from the region (Friesische Wehde)
- 02
Raw material storage
- 03
Preparation (soaking house, double-shaft mixer)
- 04
Shaping via stiff-mud extrusion press
- 05
Cutting to size with the harp cutter
- 06
Drying in the drying chamber (approx. 72 hours)
- 07
Setting by setting robot
- 08
Firing in tunnel kilns at up to approx. 1200 °C
- 09
Quality control in the laboratory
- 10
Loading and dispatch
Raw materials and firing technology
Bockhorn Clay
Regional raw material from the Friesische Wehde, the basis of the clinker bricks' characteristic play of colours.
Fired Clay (Clinker)
Fired at high temperatures of up to approx. 1200 °C, with low water absorption (<6 wt-%), high compressive strength (>44 N/mm²) and frost resistance.
Dimensional Tolerance Class T2 (DIN EN 771-1)
Highest requirement class for facing clinker bricks with respect to dimensional tolerances.
Grabstede Works
Bockhorn-Grabstede
DEProduction, administration and exhibition
- Materials
- Bockhorn clay, fired clay
- 2 tunnel kilns
- Stiff-mud extrusion press
- Double-shaft mixer
- Harp cutter
- Setting robot
- Drying chamber
- Soaking house (raw material preparation)
Industries
Processes & technical limits
| Processes | Tolerance | Max. part | Weight | Lot size | Materials |
|---|---|---|---|---|---|
| Clinker production (extrusion/shaping, drying, firing in tunnel kiln)Casting | – | – | – | – | Bockhorn clay, Clay |
| Manufacture of facing clinker bricksCasting | Dimensional tolerance class T2 (DIN EN 771-1) | – | – | – | Clinker (fired clay), Bockhorn clay |
| Manufacture of paving clinker bricksCasting | – | – | – | – | Clinker (fired clay), Bockhorn clay |
| Manufacture of speciality bricks/speciality clinker bricks (incl. manually smoothed corner clinkerCasting | – | – | – | – | Clinker (fired clay) |
| Manufacture of thin brick slips (Eco thin brick slips – one brick, two slips)Casting | – | – | – | – | Clinker (fired clay) |
| Drying in drying chamberCasting | – | – | – | – | Clinker (fired clay) |
| Firing at high temperatures of up to approx. 1200 °CHeat treatment | – | – | – | – | Clinker (fired clay) |
| Quality control / in-house production control (laboratory)Testing | – | – | – | – | – |
| Raw material extraction (clay mining) and preparationCasting | – | – | – | – | Bockhorn clay |
7 Anlagen & Maschinen
| Machine | Manufacturer / model | Quantity | Working area | Year built | Site |
|---|---|---|---|---|---|
| Tunnel kiln | – | 2 | – | – | Bockhorn-Grabstede |
| Stiff-mud extrusion press | – | – | – | – | Bockhorn-Grabstede |
| Double-shaft mixer | – | – | – | – | Bockhorn-Grabstede |
| Harp cutter | – | – | – | – | Bockhorn-Grabstede |
| Setting robot | – | – | – | – | Bockhorn-Grabstede |
| Drying chamber | – | – | – | – | Bockhorn-Grabstede |
| Soaking house (raw material preparation) | – | – | – | – | Bockhorn-Grabstede |
Additional services
Reference customers
Quality and Standards
The products are subject to continuous in-house production control from raw material intake to final inspection as well as regular external surveillance by Güteschutz Ziegel e.V. Facing clinker bricks meet the highest requirement classes of DIN EN 771-1 (among others T2, compressive strength >44 N/mm², water absorption <6 %, salt class S3); paving clinker bricks exceed DIN EN 1344 and DIN 18503 (R1, T4, A3, FP100, U3).
| Evidence | Bockhorn-Grabstede |
|---|---|
| DIN EN ISO 50001:2018 (Energy Management) | |
| DIN EN 771-1 (facing clinker bricks) | |
| DIN EN 1344 / DIN 18503 (paving clinker bricks) | |
| External surveillance by Güteschutz Ziegel e.V. |
Company History
- 1906
Heinrich Uhlhorn, Wilhelm Müller and Dietrich Schmidt purchased a brickworks that had been operating for several years in Bockhorn-Grabstede; it has remained family-owned ever since.
- 1960er
Conversion of the initially peat-fired ring kilns to gas-fired tunnel kilns.
Comprehensive modernisation of the production facilities; production in two tunnel kilns at the Grabstede works.