SKF Power Transmission products

Standard letter



Introduction
The objective of this letter is to cover additional technical specifications, complementing
the information already covered in the "SKF Power transmission products" catalogue
(publication 11015) and its online version available on www.skfptp.com.

All the SKF Power transmission products are manufactured according to the highest
quality standards, making use of all relevant techniques in the manufacturing processes
(e.g. SPC – Statistical Process Control), with the guarantee of customer satisfaction as
ultimate goal. In addition, complete traceability is ensured through an experienced
marking and labelling system, and a quality focused organisation behind each process.

In addition, it is worth emphasizing that all SKF Power transmission products are fully
interchangeable with products from other common brands available in the market place.

Please contact your local SKF Authorized Distributor in case of any further questions
related to SKF Power transmission products.


SKF Chains
SKF Chains completely conform to international standards (ISO) and other advanced
industrial standards (i.e. ANSI and DIN) as shown below:
• Short pitch transmission precision roller chains are manufactured according to
ISO 606- 1994, ASME B29.1M-1993 and DIN 8187/DIN 8188;
• Double pitch precision roller chains for transmission and conveyors are manufactured
according to
ISO 1275-1995, ASME B29.3M-1994/AMSE B29.4M-1994 and DIN 8181-2000;
• Short pitch transmission precision bush chains are manufactured according to
ISO 1395-1997, ASME B29.12M-1997 and DIN 8154/DIN 8164;
• Steel roller chains/attachments (types S and C) are manufactured according to
ISO 487-1998, ASME B29.19M-1996 and DIN 8169-1997;
• Conveyor chains/attachments are manufactured according to
ISO 1977-2000, ASME B29.15M-1997 and DIN 8165/DIN 8166/DIN 8167;
• Heavy duty cranked link transmission chains are manufactured according to
ISO 3512, ASME B29.10M-1997 and DIN 8182
• Leaf chains are manufactured according to
ISO 4347-1992, ASME B29.8M-1983 and DIN 8152;
• Welded steel type cranked link drag chains are manufactured according to
ISO 6971-2002 and ASME B29.200-2001;
• Welded steel type cranked link mill chains are manufactured according to
ISO 6972-2002 and ASME B29.200-2001;
• Silent chains are manufactured according to
ASME B29.2M-1982 and DIN 8190;
• Open barrel steel pintle type conveyor chains/attachments are manufactured
according to ASME B29.25M-1994;
• Oil field chains are manufactured according to API SPEC 7F-1993;
• Hollow pin chains are manufactured according to ASME B29.27M-2001 and DIN 8168;
Main materials used in the chain construction:
Parts description Material specification
Side plate 45Mn, 40Cr, 35CrMo
Premium carbon steel no. 45
Roller Premium carbon steel no. 10
Premium carbon steel no. 45
Bush 20Mn
Premium carbon steel no. 20
Pin 35CrMo, GCr15, 30CrMnTi, 40Cr, 20CrMnMo


SKF Sprockets
All SKF Sprockets are manufactured according to ISO606 & ASME B29.100 standard.
The sprockets are made from steel material C-45 and premium carbon steel no. 20
on hub material if welded. For some special sprockets gray cast iron HT250
or cast iron 250 material is used.
Sprocket 25T and below are hardened as standard (typically 35-40 HRC).
This is only valid for sprocket teeths manufactured with steel material C-45.
Surface treatment such as black oxide and zinc plating can be offered upon request.
Tolerances are machined according to DIN 8196.
All sprockets are completely deburred and protected with rustproof oil.


SKF Belts
SKF Belts are manufactured to a "worldwide" specification, PTP-0299 (Feb 2000),
which is compatible with all commonly used standards:
 
• wrapped and cogged belts are manufactured according to GB 1171 and BS 3790;
•
 timing belts are in accordance with quality standards
GB/T13487-1992 and GB/T11616-1989;
• length and tolerance control of MXL, XL, L, H, XH, XXH profiles are done in accordance with ISO 5296-1;
• measurement tolerance testing is done in accordance with ISO 4184;
• SKF Belts* are manufactured to be anti-static and as such comply with ATEX directive
requirements (static conductivity testing is done in accordance with ISO 1813);
• equipment testing is done in accordance with ISO 255-1990.
All the belts are manufactured and measured to their "Datum" (Ld), "Pitch" (Lp) or "Working"
(Lw) length. (All these definitions are the same and relate to an exact set-width in detailed
measurement of pulleys, taking place under a specific load per belt section).

All "V" and wedge belts are manufactured to the SKF own "MATCHED SET" tolerances when-
ever produced, and stay matched, implying they are installed to the relevant "Installation Ten-
sion" value, using the correct equipment, and that they are fitted in pulley grooves under rea-
sonable conditions.

It is recommended that new belts should not be mixed with old belts on the same drive. The same is
valid for different constructions and different manufacturers’ brands.

The "matched set bands" work well in practice, provided belts are tensioned to the tension-
ing instructions for the general respective belt section/construction. All belts are actually
manufactured to the branded size plus/minus a set tolerance, which relates to the "matched-
set" tolerance band (most internationally known standards allow a larger deviation from the
branded size to the actual measured length).

SKF Belts* are oil and heat resistant within the properties and capabilities of the "Polychloro-
prene" ("Chloroprene", "Wingprene" and "Neoprene" are other names for the same synthetic
oil derived rubber compound), but the belts are not "fire resistant". Recommended ambient
temperature range is from –30° C to +70° C. Note that belt lifetime will be affected in case
these limits are not respected.
Main materials used in "V" and wedge belts:
• Polyester
• Polychloroprene
• Natural Rubber
• SB Rubber (Styrene-Butadiene)
• PB Rubber (Poly-Butadiene)
• Cotton
• Sulphur
• Carbon black
• Plus small quantities of other material
Main materials used in timing belts:
  Classical HiTD Polyurethane metric (T2.5, T5, T10, AT2.5, AT5, AT10) Polyurethane metric (T2.5, T5, T10, AT2.5, AT5, AT10)
  (MXL, L, H, XH,XXH) (3M, 5M, 8M, 14M) Truly Endless Open Ended
Tensile member (cord) Fiberglass Fiberglass Steel cord / Kevlar cord Steel cord / Kevlar cord
Tooth compound CR C Polyurethane Polyurethane
Tooth facing fabric Nylon Nylon no fabric Nylon available
Backing fabric CR CR no fabric Nylon available
Belts could be stored for 7 (seven) years without affecting expected working life if the storage
is done in optimum conditions.
SKF Belts* are branded as shown in below picture:

Examples
B 1460 => section B + pitch length 1460 mm
B 56 => section B + inside length 56 inches

* except SKF Cogged Raw Edge Belts 


SKF Pulleys
Classical and trapezoidal inch pitch timing pulleys (MXL, XL, L, H, XH, XXH) are manu-
factured according to ISO 5294.
 
Metric pitch series timing pulleys (T/AT) are manufactured according to DIN 7721.

All SKF V-belt Pulleys are manufactured to the standards ISO 4183, DIN 2211,
ANSI Narrow V-belt pulley IP-22 and the ANSI Classical V-belt pulley IP-20.
They are interchangeable with type SPA, SPB, SPC and SPZ. The pulleys are made from
cast iron G3000 (GG ) to American standard "SAEJ431AVG96".

Following are the requirements of G3000:
• Tensile strength ³ 207Mpa
• Hardness ³ HB 187-241
• Chemical composition C 3,1-3,4 %, Si 1,9-2,3 %, Mn 0,6-0,9 %, S £ 0,15 %, P £ 0,15%
After being machined, pulleys are phosphatised and treated with rustproof oil.

All pulleys are statically balanced to 6.3 according to ISO 1940. After balanced the pulleys
are suitable for the linear speed of not more than 35m/sec. Dynamic balancing can be
provided on request. SKF can issue a certificate stating that all pulleys are dynamically
balanced in case of a special customer request.


SKF Couplings
SKF Flex-, Chain-, FRC-, Jaw Couplings and Universal Joints are manufactured according
to established market standards and are fully interchangeable with other brands:
• Metric bore keyway machined according to BS 4231:Part 1 and DIN 6885;
• British imperial bore keyway machined according to BS 46:Part 1; and
• American imperial bore keyway machined according to ASME B17.1.

SKF Grid, Gear and Rigid couplings are manufactured according to established industrial standard,
which is acceptable throughout the world.
Parts description
Material specification
SKF Flex coupling
SKF Flex Spacer coupling 		Flange in grey cast iron HT250; tyre available in nitrile
or chloroprene (FRAS); rubber and spacer in grey cast
Iron HT250.
Chain coupling Flange in premium carbon steel no. 45 and cover
available in aluminium and plastic.
FRC coupling Flange in grey cast iron HT250 and elements available
in nitrile or chloroprene (FRAS) rubber.
Jaw coupling Flange in grey cast iron HT250; spacer in aluminium
and insert available in nitrile, urethane and hytrel.
Grid coupling
Hub in steel SM45C equivalent to AISI 1045;
grid member spring steel grade HSWR82B (equivalent to SAE 9254), horizontal and vertical split cover as following:
Horizontal split cover sizes:1020 to 1170Die cast aluminium Alloy ALDC7/8; (ASTM380)
1180 to 1210Cast with powder coated finish
1220 to 1240Fabricated steel
Vertical split cover all sizes:Steel SS 1045
Gear coupling Sleeve and hub in steel SM45C equivalent to AISI 1045.
Rigid coupling All components manufactured in grey cast iron HT250.
Universal Joint Premium carbon ste
SKF Gear Couplings are interchangeable, half to half, to industries standard using AGMA bolt
pattern.
Every coupling is protected by a specific treatment, which depends on the material or type of
packaging: (1) phosphate coating, (2) blackening, (3) spray painting or (4) anti-corrosion oil.


SKF Bushings and Hubs
SKF Taper Bushings, QD Bushings, Weld-on and Bolt-on Hubs are manufactured according
to established market standards and are fully interchangeable with other brands.

Metric bore keyway machined according to BS 4235: Part 1 and DIN 6885.

Imperial bore keyway machined according to BS 46: Part 1.
Material use:
• Taper bushing – grey cast iron HT250
• QD bushing – grey cast iron HT250
• FX keyless bushings – C45 steel
• Weld on hubs – premium carbon steel 20 (C20)
• Bolt on hubs – grey cast iron HT250
Phosphate coating and blackening are used to improve corrosion resistance.


Last revision: 10.06.2015
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