SIST EN 3291:2001

• Abstract:

  This standard specifies the characterisitics of single row self-aligning roller bearings in steel, cadmium plated, of diameter series 3 and 4 designed to withstand only slow rotations, oscillations and/or swivelling under load. They are intended for use between fixed and moving parts of the aircraft structure and their control mechanisms.

• Status: Published
• Publication Date: 31-Dec-2000
• ICS: 49.035 - Components for aerospace construction
• Technical Committee: SS SPL - Technical Board for the general field
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Jan-2001
• Due Date: 01-Jan-2001
• Completion Date: 01-Jan-2001
• Ref Project: EN 3291:1994 - Aerospace series - Bearings, airframe rolling - Single row self-aligning roller bearings in steel, cadmium plated - Diameter series 3 and 4 - Dimensions and loads

• Referred By: SIST EN 3280:2011 - Aerospace series - Bearings, airframe rolling, rigid or self-aligning - Technical specification
• Effective Date: 28-Jan-2026

SIST EN 3291:2001 is a Slovenian standard published by SIST for aerospace airframe rolling bearings. It specifies the characteristics, dimensions and loads of single row self-aligning roller bearings in steel, cadmium plated, for diameter series 3 and 4, used where the bearing sees slow rotations, oscillations and/or swivelling under load. These bearings are intended for fixed and moving parts of the aircraft structure and their control mechanisms.

What does SIST EN 3291:2001 specify?

SIST EN 3291:2001 specifies a particular bearing family for aircraft applications, with the focus on dimensions and loads. It is a product standard for single row self-aligning roller bearings made of steel and cadmium plated, not a general guide to bearing design.

The scope limits the application to bearings designed for slow motion under load. In practice, that means the document is meant for selecting and checking bearings used in movements that are not continuous high-speed rotation, but back-and-forth or limited pivoting service in airframe assemblies.

The standard is aimed at aircraft structure and control mechanisms, so the values in the document matter when a designer, buyer, or quality team needs a bearing that fits a defined series and duty in an aerospace installation.

What are the key requirements of SIST EN 3291:2001?

SIST EN 3291:2001 defines the bearing type, the material and surface protection, the diameter series, the intended motion, and the load-related characteristics that go with that bearing family. Those points are the basis for design selection and procurement.

• Single row self-aligning roller bearings - the standard applies to one-row roller bearings that can accommodate misalignment. In practice, this matters where shaft and housing alignment is not perfect.
• Steel construction - the bearings are specified in steel. For users, this sets the basic material family expected for the part.
• Cadmium plated - the bearings are cadmium plated. This is important for specifying the protected surface condition that must be matched by the supplier.
• Diameter series 3 and 4 - the standard covers only these diameter series. That lets designers and buyers identify the correct dimensional family instead of a different bearing size series.
• Slow rotations, oscillations and/or swivelling under load - the intended duty is limited to these motions. This helps engineers avoid applying the standard to a service condition outside its scope.
• Aircraft structure and control mechanisms - the bearings are intended for use between fixed and moving parts in these aircraft assemblies. In practice, this tells the user where the bearing is suitable.
• Dimensions and loads - the document provides the dimensional and load data for this bearing type. That is the information needed to specify, compare, and verify parts during design and quality control.

What terms does SIST EN 3291:2001 define?

Airframe rolling bearings are rolling bearings used in aircraft structural applications, where size, motion, and load capability must match the airframe duty.

Single row means the bearing has one row of rolling elements. This helps identify the bearing arrangement and its load-carrying style.

Self-aligning means the bearing can accommodate angular misalignment between mating parts. In practice, this is useful where exact alignment cannot be guaranteed.

Roller bearings use rollers rather than balls as the rolling elements. This is relevant because the bearing type is chosen for its load and motion characteristics.

Cadmium plated means the bearing has a cadmium coating on its surface. For users, this is part of the product specification and purchase description.

Diameter series 3 and 4 identifies the dimensional series covered by the standard. This is the key series designation a buyer or designer uses when matching the bearing to an installation.

Oscillations are repeated back-and-forth movements. The term matters because the standard is written for this kind of service, not only continuous rotation.

Who uses SIST EN 3291:2001?

SIST EN 3291:2001 is used by aerospace design engineers, bearing suppliers, procurement teams, and quality managers working on aircraft structure and control mechanisms. They use it to select the correct bearing series, define the required dimensions and load characteristics, and check that supplied parts match the specified bearing family.

It is also relevant to organizations that receive, inspect, or approve aerospace parts, because it gives a common reference for the bearing type named in the standard.

What changed in SIST EN 3291:2001 from the previous edition?

SIST EN 3291:2001 is the Slovenian standard identified as identical to EN 3291:1994.

Which standards are used with SIST EN 3291:2001?

EN 3291:1994 - the document to which SIST EN 3291:2001 is identical.

What does the SIST EN 3291:2001 document contain?

The document presents the multilingual title and identification information, followed by the scope for the bearing family named in the title. Its technical content is centered on the bearing characteristics, dimensions, and loads for single row self-aligning roller bearings in steel, cadmium plated, diameter series 3 and 4.

For practical use, that means the standard serves as a product definition for design selection, procurement, and incoming verification in aerospace applications. It is the reference a reader would use when they need the exact bearing type for aircraft structure or control mechanism assemblies.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aerospace series - Bearings, airframe rolling - Single row self-aligning roller bearings in steel, cadmium plated - Diameter series 3 and 4 - Dimensions and loadsLuft- und Raumfahrt - Flugwerklager - Einreihige Tonnenlager aus Stahl, verkadmet - Durchmesserreihen 3 und 4 - Maße und BelastungenSérie aérospatiale - Roulements pour structures d'aéronefs - Roulements en acier, cadmiés, a rotule, sur une rangée de rouleaux - Séries de diametre
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