Custom Gasket Order: A Technical Guide for Dimensions, Material, and Thickness
Custom-cut gaskets address a much wider need than the repair of a single connection. Manufacturing facilities require custom-sized gaskets for maintenance and planned shutdown schedules; machinery manufacturers for serial production lines; and sectors such as the defense industry, rail systems, and energy for project procurement based on technical drawings and specifications. Whether the order is for a single piece or for serial production, the accuracy of the quote and the delivery time depend on the technical information provided during the request phase.
This guide brings together the information needed by procurement, supply, maintenance, and project teams when preparing a custom-cut gasket request, including measurement methods, material and thickness selection, and the SUARO TITAN workflow from sample to serial production.
In brief
- Custom-cut gaskets are not just for singular repairs; factories, machinery manufacturers, the defense industry, rail systems, and energy plants place serial and project-based orders.
- Gaskets for standard pipe flanges are defined by flange standard, nominal diameter, pressure rating, and gasket type. PN and Class series are not interchangeable.
- For non-standard connections, measurements should be taken from the flange surface where the gasket sits, if possible.
- The material is determined by the fluid, operating temperature, and pressure combined; thinner gaskets should be preferred whenever possible.
- For fully submitted requests, pricing and lead times are notified on the same day following technical evaluation.
Contents
- Sectors and order types
- Gasket definition for standard flanges
- Taking measurements for ring and bolted gaskets
- Transferring geometry for custom-shaped gaskets
- Material selection
- Thickness selection
- Production methods
- Workflow from request to shipment
- Quality assurance
- Checklist for request for quote
- Common mistakes and best practices
01 · Sectors
Sectors and order types
A custom-cut gasket is a gasket produced from sheet material in the required inner and outer dimensions, bolt pattern, and thickness for connections not found in standard sizes. This need is also referred to as a custom-sized gasket or a gasket according to a drawing in the industry. Since it is encountered in every connection where the dimensions are specific to the equipment, requests are not limited to a single sector:
Production facilities and factories
Pump, valve, compressor, and process connections; bulk requests for maintenance and planned shutdown periods.
Defense industry
Production according to technical drawings and specifications; material, tolerances, and required documentation are specified during the quotation phase.
Rail systems and high-speed trains
Fire behavior of the gasket material in rail vehicle projects may be required according to EN 45545-2; the hazard level (HL1–HL3) is determined according to the operating conditions of the vehicle.[18]
Energy and boiler systems
Boiler and burner covers, steam and hot oil lines, generator sets.
Chemical and process industry
PTFE-based flange and equipment gaskets for aggressive fluid lines.
Marine and shipping
Marine engines and pump, valve, and flange connections.
Construction machinery
Engine and equipment gaskets; production according to samples for models where spare parts are unavailable.
Machinery and equipment manufacturers (OEM)
Fixed-dimension production according to drawings for serial parts of machinery manufacturers.
Sector-specific requirements (e.g., fire behavior class, requested documentation) are included in the project specification. Sharing the specification during the request phase ensures that the quote is prepared correctly.
From single pieces to serial and project procurement
A single maintenance part and a serial order rely on the same technical information; what changes are the production method and the quantity. Specifying which type the request falls under from the beginning ensures that the correct method is determined in the initial quote.
| Order type | Typical need | Workflow |
|---|---|---|
| Single and urgent need | Breakdowns and shutdowns, machinery with unavailable spare parts, gaskets with unknown dimensions | Laser cutting from sample, dimension, or drawing; no mold waiting. |
| Serial production | Gaskets used continuously by machinery and equipment manufacturers | Fixed-dimension production using press and mold following sample approval. |
| Project procurement | Factory maintenance programs, defense and rail system projects | Production according to technical drawing and specification; multi-item requests can be forwarded as a single list. |
02 · Pre-check
Gasket definition for standard flanges
The dimensions of non-metallic flat gaskets used in pipe flanges are determined by standards. If the flange complies with one of these standards, the gasket can be defined with the flange standard, nominal diameter, pressure rating, gasket type, material, and thickness information without the need for measurement.
| Flange series | Flange standard | Gasket dimension standard | Scope |
|---|---|---|---|
| PN series (European) | EN 1092-1 … EN 1092-4 | EN 1514-1[1] | PN 2.5 – PN 63; up to DN 4000[1] |
| Class series (American) | ASME B16.5, B16.47, B16.1, B16.24 | ASME B16.21[3] · European equivalent EN 12560-1[2] | Class 25 – Class 900 according to flange standard[3] |
| Information | Example | Description |
|---|---|---|
| Flange standard | EN 1092-1 · ASME B16.5 | Determines which table the gasket dimension is taken from. Two standards should not be mixed in a single connection.[7] |
| Nominal diameter | DN 100 · NPS 4 | DN and NPS dimensions are not exactly the same.[7] |
| Pressure rating | PN 16 · Class 150 | PN and Class ratings are not equivalent: Class 150 corresponds to PN 20; Class 300 to PN 50 (ISO 7005).[6] |
| Gasket type | FF · IBC · TG · SR | EN 1514-1 types: FF Full Face, IBC Inside Bolt Circle, TG Tongue-Groove, SR Spigot-Recess.[1] |
| Material and thickness | Graphite · 2 mm | Selected according to operating conditions (see 05 and 06). |
Example: same size, different gasket
According to EN 1514-1, a DN 100 PN 16 IBC gasket is 115 × 162 mm.[4] According to ASME B16.21, an NPS 4 Class 150 ring gasket is 4.50″ × 6.88″ (114.3 × 174.8 mm).[5] Therefore, the flange standard must be specified in the order. EN 1514-1 has replaced DIN 2690–2692; as old DIN dimensions differ in some sizes, checking is recommended in existing facilities.[4]
If the flange standard and pressure rating are not known, or if the connection is not a pipe flange, the dimension must be taken using the method below.
03 · Measurement
Taking measurements for ring and bolted gaskets
Measurements should be taken with calipers, if possible, from the flange surface where the gasket seats. A used gasket is not reliable on its own for measurement, as it may be compressed, damaged, or distorted; it can, however, be used as a reference for shape and hole layout. Measuring each diameter at at least two different points helps identify ovality or measurement errors.
| Symbol | Measurement | Definition and measurement note |
|---|---|---|
| d1 | Inner diameter | The opening through which the fluid flows. The gasket inner diameter should match the pipe inner diameter; a smaller inner diameter will protrude into the flow, causing turbulence and erosion.[10] |
| d2 | Outer diameter | In ring (IBC) gaskets, it remains within the bolt circle; the gasket is centered by resting against the bolts.[4] |
| k | Bolt hole circle diameter | The distance between the centers of two opposite holes.[8] |
| L | Hole diameter | The diameter of the bolt hole. |
| n | Number of holes | The total number of bolt holes. |
| t | Thickness | Gasket thickness (for selection, see 06 · Thickness selection). |
Determining the bolt hole circle diameter
Since measuring the hole center directly is difficult, the bolt hole circle diameter (k) is determined indirectly:
- Even number of holes: If the hole diameters are equal, measure the distance from the inner edge of one hole to the outer edge of the hole directly opposite. This value is equal to the bolt hole circle diameter.[8]
- Odd number of holes: Measure the distance (a) between the centers of two adjacent holes and calculate the bolt hole circle diameter using the formula below.[9]
k = a ÷ sin(180° ÷ n)
Example: For a 5-hole flange, if a = 100 mm, then k = 100 ÷ sin 36° ≈ 170 mm
04 · Geometry
Transferring geometry for custom-shaped gaskets
For irregular geometries such as covers, sumps, and pump housings, transferring the entire shape is more reliable than taking measurements one by one. Our accepted methods, listed in order of accuracy, are as follows:
1 · Highest accuracy
Technical drawing or DXF
Cutting is done directly from the file; no measurement interpretation is required. PDF and DXF formats are accepted.
2 · High accuracy
Physical sample
The old gasket or part is sent to us; measurements are taken from the sample at our facility, and production begins upon your approval.
3 · Medium accuracy
Tracing the surface
The gasket surface is lightly inked and pressed onto paper, or the edges are traced with a pencil. A 100 mm reference line must be added to the paper.
4 · Preliminary assessment
Photograph with measurement
The part should be photographed from directly above at a right angle with a ruler placed next to it. Angled shots cause perspective distortion.
Sending samples
Samples can be sent to: Yayla Mah. Cami Sok. No:35 İç Kapı No:1, Şişli / İstanbul. Please include company name and contact details with shipments; factory visits are by appointment only.
05 · Material
Material selection
Gasket material is determined by three basic parameters: fluid (water, steam, oil, fuel, chemical, gas), operating temperature, and pressure. Temperature and pressure are evaluated together; for sheet materials, maximum temperature and maximum pressure cannot be applied simultaneously. The table below provides a general framework for initial selection.
| Material | Temperature range | Typical use | Point of note |
|---|---|---|---|
| Graphite | Up to approx. 400 °C for long-term use in air[11] | Steam, hot oil, boilers, exhaust, and flange connections | Consult the sheet manufacturer for use above 400 °C in oxidizing environments; resistance is higher in steam.[11] |
| Composite fiber sheet aramid fiber + NBR binder, asbestos-free “klingerit” type |
Continuous ~200 °C; short-term upper limit ~370–400 °C depending on quality[12, 13] | Water, oil, fuel, and general industrial fluids | Maximum temperature and pressure cannot be applied simultaneously; refer to the manufacturer's P-T ratings.[12, 13] |
| PTFE (teflon) | –268 / +260 °C (modified PTFE product data)[14] | Acids, bases, and aggressive chemicals | Cold flow is observed in cut and expanded pure PTFE sheets; modified and filled PTFE sheets reduce this effect.[15] |
| EPDM | ≈ –57 / +150 °C[16] | Hot water and steam, air, outdoor use; resistant to ozone and aging[16] | Not suitable for mineral oil products (oil, grease, fuel).[16] |
| NBR | ≈ –34 / +100 °C (short-term 121 °C)[16] | Mineral oil and grease, diesel and fuel oil, HFA / HFB / HFC hydraulic fluids[16] | Not resistant to weather and ozone; not suitable for fuels with high aromatic content.[16] |
| FKM | ≈ –26 / +204 °C[16] | Mineral oil and grease, gasoline, aromatic hydrocarbons[16] | Not suitable for superheated steam, amines, and alkalis.[16] |
| Silicone | ≈ –54 / +204 °C (+260 °C in special blends)[16] | Air, animal and vegetable oils, wide temperature range[16] | Low mechanical strength; not suitable for hydrocarbon fuels or superheated steam above 121 °C.[16] |
| Metal / multilayer steel | Depending on application | Cylinder head, manifold, and connections requiring high surface pressure | Application-specific; selected based on engine or equipment manufacturer specifications. |
Technical note
Values in the table are general guidelines. Elastomer ranges are based on general values in the Parker O-Ring Handbook[16]; for sheet materials, definitive limits are found in the product's data sheet. If you are unsure about the material, simply specify the fluid, temperature, and pressure in your request, and the appropriate material will be suggested with the quote.
06 · Thickness
Thickness selection
The basic principle is to choose a thin gasket whenever possible; a thick gasket is selected only when the condition of the flange surface requires it.[17] Thickness is determined by the condition of the flange and the function of the connection:
| Connection condition | Recommendation | Reasoning |
|---|---|---|
| Flat and undamaged flange surface | Thin gasket (e.g., 1/16″ ≈ 1.6 mm) | Blow-out resistance increases because the surface exposed to pressure is smaller; bolt load is better maintained as creep relaxation is lower.[17] |
| Warped, pitted, or damaged flange; low-pressure, large-diameter flange | Thicker gasket (e.g., 1/8″ ≈ 3.2 mm) | Adapts better to uneven surfaces; however, creep relaxation increases, and bolts may need to be re-tightened.[17] |
| Connection where distance between parts must be maintained (e.g., split-casing pump) | Specified or existing thickness | In this case, the compressed thickness of the gasket is the determining factor.[17] |
07 · Production
Production methods
The cutting method is determined during the technical assessment stage based on order quantity, material, and geometry. Since molds are prepared in our facility, we are not dependent on external suppliers, which shortens lead times.
Mass production
Press and mold
Fast, dimensionally consistent production for high and recurring quantities.
Samples and low volume
Laser cutting
Cutting directly from technical drawings or DXF files without waiting for molds.
Mold production
CNC mold machining
Molds for dimensions not found in the catalog are machined using CNC.
08 · Process
Work process from request to shipment
Request
Dimensions, drawings, or photos are submitted via the quote form, WhatsApp, or email; samples are provided if necessary. Lists for multi-item projects can be sent via email in a single batch.
Technical evaluation
Dimensions are verified, material and cutting method are determined; additional measurements are requested if information is missing.
Price and lead time
Unit price and delivery time are provided on the same day following the technical evaluation.
Sample approval
Following quote approval, the necessary mold and first-part production are carried out.
Serial production
Production commences upon approval; thickness, dimensions, and edge integrity are checked in every batch.
Shipment
Items are shipped after packaging and labeling; outgoing orders are prepared until 16:00 on weekdays.
09 · Quality
Quality assurance
Production is carried out under an ISO 9001:2015 certified quality management system. Thickness, dimensions, and edge integrity are checked in every production batch. As SUARO TITAN, we have been manufacturing engine and industrial gaskets in our facility in Şişli / Istanbul since 1997.
Since 1997
Gasket production, Istanbul
ISO 9001:2015
Certified quality management system
Same-day
Price and lead time response
10 · Request
Checklist for quote requests
Providing the following information in full ensures that the evaluation is completed without the need for additional questions:
11 · Application
Common mistakes and best practices
| Common mistake | Best practice |
|---|---|
| Taking measurements from crushed or damaged gaskets | Measure from the flange face if possible; use the old gasket for shape and bolt hole layout reference. |
| Measuring bolt hole circle diameter from the wrong edges | Measure center-to-center, or from the inner edge of one hole to the outer edge of the opposite hole.[8] |
| Confusing PN and Class series | Specify the flange standard; DN 100 PN 16 and NPS 4 Class 150 gaskets have different dimensions.[4, 5] |
| Choosing an inner diameter smaller than the pipe bore | Match the inner diameter with the pipe bore; a gasket protruding into the flow causes turbulence and erosion.[10] |
| Requesting only a "gasket" | Share information on material, temperature, pressure, and application.[8] |
| Sending photos taken at an angle | Take photos from directly above, at a right angle, and with a ruler for scale. |
| Failing to specify quantity | Specify the quantity; single pieces and serial orders are produced using different methods. |
Custom production request
Submit your custom gasket request
Whether for single pieces, serial production, or project supply; your production requests based on dimensions, technical drawings, or samples will be evaluated technically, and price and lead time will be provided on the same day. Our production is intended for corporate clients only.
Akduman Conta Sanayi ve Ticaret Ltd. Şti. · SUARO TITAN
Yayla Mah. Cami Sok. No:35 İç Kapı No:1, Şişli / İstanbul
Tel: +90 212 237 16 29 · Email: info@suarotitan.com
Related content
- Custom gasket manufacturing: material options and production methods
- Finding the right gasket via OEM number and engine code
- Online Catalog: Searching for engine gaskets by OEM number
References
- EN 1514-1:2024 · Dimensions of gaskets for PN-designated flanges, Part 1 (CEN, iTeh preview): Scope, PN and DN range, FF / IBC / TG / SR gasket types
- DIN EN 12560-1:2024 · Dimensions of gaskets for Class-designated flanges, Part 1 (DIN, table of contents): European standard for gasket dimensions for Class-series flanges
- ASME B16.21-2021 · Nonmetallic Flat Gaskets for Pipe Flanges (ASME, table of contents): Covered flange standards and pressure classes
- Zickwolff · Flat gaskets to EN 1514-1, form IBC: DN 100 PN 16 IBC dimension, centering with bolts, relationship to DIN 2690–2692
- AMES · ASME B16.21 Class 150 nonmetallic gasket dimensions: NPS 4 Class 150 ring gasket dimensions
- The Engineering ToolBox · Flanges: PN pressure ratings: ASME Class and ISO 7005 PN equivalents
- Project Materials · How to order EN 1092 flanges: Difference between DN and NPS dimensions, avoiding confusion of standards
- PAR Group · How to measure a gasket: Measuring bolt hole circle diameter, information required for quotes
- Machining Doctor · Bolt hole circle formulas: Bolt hole circle diameter formula from distance between adjacent holes
- GPT Industries · Matching to the pipe bore: Matching gasket inner diameter with pipe bore
- SGL Carbon · SIGRAFLEX Thermal Stability (technical info): Temperature resistance of graphite in air and steam
- Garlock · BLUE-GARD Style 3000 spec sheet: Temperature and pressure ratings for aramid/NBR fiber sheet
- PAR Group · KLINGERsil C-4400: Aramid/NBR fiber sheet; maximum temperature and pressure not applicable simultaneously
- Garlock · GYLON Style 3510 spec sheet: Modified PTFE sheet temperature range
- Garlock · GYLON gasketing: Cold flow in cut and expanded PTFE sheets
- Parker · O-Ring Handbook ORD 5700: Temperature ranges and chemical compatibility for NBR, EPDM, FKM, and silicone
- Garlock · Gasket thickness selection: Thin and thick gasket selection
- Measurlabs · EN 45545-2 fire testing of train materials: Fire requirements for railway vehicle materials, HL1–HL3, R22 / R23
The full text of the standards can be obtained from the relevant standards organizations. The current data sheet for the sheet or elastomer used should be taken as the basis for precise values.