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The quality of the goods we offer is a priority in our policy.


The international standard BDS (Bulgarian National Standard) EN ISO 9001: 2015 is established with the aim of guaranteeing the ability of the organization to constantly provide quality products and services, which match the designated requirements.

The introduction of a quality management system in Trierra LTD, according to the international standard BDS EN ISO 9001:2015 is a strategic decision of the upper management, which has been covered for 16 years with yearly control audits and 6 recertification audits conducted by the certification organization SGS Bulgaria. Trierra’s first certificate was granted in July 2003, followed by recertification audits in July 2006, July 2009, July 2012, and July 2015.

The last audit for recertification on the new version of the standard BDS EN ISO 9001: 2015 was passed successfully in July 2018. A certificate was granted with №HU03/0148 by SGS Bulgaria with an expiry date 21 July 2021.

Certificate Coverage

Import, export, trade with industrial and automotive bearings and other machine elements.

Laboratory Testing Complex

Trierra has invested in the construction of a laboratory testing complex – LTC Trierra, in which highly qualified technical specialist test separate bearing lots from the various manufacturers.

This is done not only for both new brands and for bearings which the firm considers offering to their clients in and out of the country, but also for control of the bearings which are already popular on the market, and for evaluation of the bearing providers.

Our LTC is equipped with the most up-to-date precise measurement machinery and stands, along with the required precise benchmarks, and the necessary engineering personnel.

The main role of the LTC in guaranteeing the quality of the bearings is the control of the accuracy parameters of the inbound and outbound production, as the size of the lot sample is as large as possible to ensure maximum legitimacy.

The bearings which we work with have to correspond to the main norms ISO and EN. The evaluation is conducted in our Laboratory Testing Complex with the following measurements:


Gauge dimensions of the various bearing types and other complimentary products.

ISO 15; ISO 355; ISO 104; ISO 113; ISO 2982, ISO 582; ISO 3030; ISO 3290;ABMA 19; ABMA 20


Technical requirements – margins of dimensions and deviations from the geometric norm, chamfer, clearances.

ISO 492; ISO 199; ISO 578, ISO 355, ISO 582; ABMA 20 and for the railway bearings - EN12080


Strength parameters, load capacity, resource, maximum rotating speed.

ISO281; ISO 15; ISO 15312


Law on Control of Foreign Trade Activity in Arms and Dual-Use Goods and Technologies.


Methodology for control in the LTC in accordance with the bearing parameters – geometrical dimensions, clearances, hardness, deviation, and vibration level.

ISO 1132; ISO15242

Tool for measuring the radial clearance of rolling bearings, type – X095C, China. Work range 10 mm ÷ 180 mm, maximal outside diameter – 280 mm. Owned by Trierra LTD

We continue to successfully offer appropriate solutions for every use of the rolling bearings, commensurate with the constructive requirements and differences of the various bearing units.

Industrial Bearings
Automotive Bearings
Oil Seals

Plovdiv, 4004
St. Byalo More 2

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