The OSK™ Industrial Boss Seal Service Package includes two 212-piece SAE Boss O-Ring kits, one Buna-N 90 and one Viton®/FKM 90, plus an O-Ring pick tool, FN LUBE PLUS silicone lubricant, and an Olypsys® Pro-Grid A4 (Letter) for O-Ring measurement. This package is built for hydraulic repair shops, service trucks, maintenance crews, and equipment repair teams that need common SAE 900 series Boss O-Rings, installation support, lubricant, and better size identification in one ready-to-use repair package.
Benefits
The OSK™ Industrial Boss Seal Service Package gives hydraulic repair teams a complete Boss fitting repair setup. It helps technicians remove old seals, measure unknown or worn O-Rings, select the right replacement, lubricate the seal, and complete the repair faster.
Customer benefits include:
- Helps reduce downtime during hydraulic repairs
- Keeps both Buna-N 90 and Viton®/FKM 90 Boss O-Rings on hand
- Supports faster service on SAE straight thread Boss fittings
- Includes Olypsys® Pro-Grid A4 (Letter) to help measure and identify O-Rings
- Includes an O-Ring pick tool for removal and installation help
- Includes FN LUBE PLUS to help reduce installation damage
- Helps service trucks and maintenance shops stay better prepared
- Reduces extra trips to the parts counter
- Makes it easier to complete more repairs with less frustration
This is not just a box of O-Rings. It is a Boss fitting repair and measurement package that helps technicians work faster, reduce mistakes, and keep equipment moving.
Correct Size Coverage
This package includes two 212-piece SAE Boss O-Ring kits. Each kit includes 20 common SAE 900 series Boss sizes used with SAE straight thread Boss fittings.
Included Boss O-Ring sizes in each kit:
- 10 each: -901, -902, -903, -904, -911, -912, -913, -914, -916, -918, -920, -924, -928, -932
- 12 each: -905, -906, -907, -908, -909, -910
Package O-Ring count:
- 212 pieces Buna-N 90 Boss O-Rings
- 212 pieces Viton®/FKM 90 Boss O-Rings
- 424 total Boss O-Rings
Included tools, lubricant, and measurement aid:
- 1 O-Ring Pick & Seal Installation & Extraction Tool, Universal 45D and Hook, Gray
- 1 FN-LUBE-PLUS-2OZ, FN LUBE PLUS 2 oz tube, high viscosity silicone lubricant
- 1 Olypsys® Pro-Grid A4 (Letter) for O-Ring measurement + 1 Year Pro Subscription
The Olypsys® Pro-Grid A4 (Letter) helps customers measure O-Rings more accurately using the Olypsys® measurement system. This is especially helpful when the original O-Ring is worn, stretched, mixed in with other seals, or hard to identify by sight.
SAE, Metric, or Specialty Kit Type
This is an SAE Boss hydraulic O-Ring service package.
It is designed for SAE straight thread Boss fittings, also called Boss fittings or SAE 900 series Boss O-Rings. These are commonly used in hydraulic systems, mobile equipment, pumps, valves, manifolds, and industrial repair work.
This is not a general AS568 shop kit and it is not a metric O-Ring kit. It is a specialty Boss seal package for SAE hydraulic Boss fitting service, with measurement support included through the Olypsys® Pro-Grid A4 (Letter).
Material Compatibility
This package includes two material options so the customer can choose the right O-Ring for the job.
Buna-N 90 is a strong choice for common hydraulic oil, petroleum oil, fuel, grease, and general shop repair. It is harder than standard 70 Duro Buna-N, which helps it perform better in hydraulic Boss fittings where pressure and extrusion resistance matter.
Viton®/FKM 90 offers better heat, ozone, UV, weathering, and chemical resistance than Buna-N. It is commonly used when the application has higher temperature, harsher fluids, petroleum fuels, aromatic hydrocarbons, or more demanding service conditions.
General material notes:
- Buna-N 90 is commonly used for petroleum oils, hydraulic oils, diesel fuel, gasoline, grease, and many shop repair applications
- Viton®/FKM 90 is commonly used for higher heat, fuels, oils, mineral oils, many hydrocarbons, and harsher industrial environments
- Viton®/FKM is not recommended for ketones, brake fluid, hot water, steam, Skydrol® fluids, ammonia gas, amines, MEK, and some low molecular organic acids
- Buna-N is not recommended for phosphate ester hydraulic fluids, ketones, ozone, UV exposure, strong acids, or long-term weather exposure
Do not assume all rubber materials work in every fluid. For critical applications, confirm the material, temperature, pressure, fluid, certification, and traceability requirements before use.
Durometer and Seal Performance
Both Boss O-Ring kits in this package use 90 durometer material.
Durometer means hardness. A 90 Duro O-Ring is harder than a 70 Duro O-Ring. That added hardness helps the O-Ring resist extrusion and deformation in higher pressure sealing areas.
Why 90 Duro matters:
- Helps resist extrusion in hydraulic Boss fittings
- Supports better performance in higher pressure connections
- Helps reduce seal damage during pressure cycling
- Can improve service life when the application calls for a harder O-Ring
- Helps reduce repeat leaks caused by using a softer seal where a harder seal is needed
For most SAE Boss hydraulic fittings, 90 Duro is the preferred hardness because these fittings often see pressure, vibration, and repeated service cycles.
Best Uses
Best applications for this Boss seal service package include:
- Hydraulic repair shops
- Field service trucks
- Mobile equipment repair
- Farm and heavy equipment repair
- Mining and construction maintenance
- Industrial maintenance departments
- Pump and valve repair
- Hydraulic manifolds and power units
- OEM maintenance areas
- Fleet maintenance shops
- Distributors supporting hydraulic customers
- Technicians who need to measure unknown O-Rings in the field
- Maintenance teams that want better O-Ring identification before ordering replacements
This package is not ideal for unknown chemicals, critical aerospace, medical, or highly specified applications unless the required material, hardness, certification, and traceability are confirmed before use.
Quality and Reliability
The OSK™ Industrial Boss Seal Service Package is built as a professional hydraulic repair solution, not a low-value filler assortment.
The value comes from:
- Correct SAE Boss size coverage
- Known material options
- Known 90 Duro hardness
- Common hydraulic fitting sizes
- Organized kit storage
- Measurement support with Olypsys® Pro-Grid A4 (Letter)
- Installation support from the included pick tool
- Reduced installation damage with FN LUBE PLUS
- Useful quantities per size
- Support from The O-Ring Store LLC
- ISO9001:2015 certified quality system
A better Boss seal package helps reduce wrong-size repairs, wasted time, and repeat failures. For the customer, that means faster service, fewer leaks, better identification, and more confidence during hydraulic repairs.
Organized Storage Case
Each Boss O-Ring kit comes organized by size so technicians can find the right Boss O-Ring faster during a repair. Clear size separation helps prevent mixing sizes and helps reduce guesswork when working under time pressure.
Organized storage helps:
- Speed up O-Ring selection
- Keep Boss sizes separated
- Improve service truck organization
- Reduce wrong-size installation
- Make refilling easier when common sizes run low
The added Olypsys® Pro-Grid A4 (Letter) gives the customer another way to verify O-Ring size when the dash number is not known.
Piece Count and Refill Value
This package includes 424 total Boss O-Rings across two 212-piece kits.
Package contents:
- 212-piece Buna-N 90 SAE Boss O-Ring kit
- 212-piece Viton®/FKM 90 SAE Boss O-Ring kit
- 1 O-Ring pick and seal installation tool
- 1 FN LUBE PLUS 2 oz high viscosity silicone lubricant
- 1 Olypsys® Pro-Grid A4 (Letter) for O-Ring measurement + 1 Year Pro Subscription
Total piece count matters, but the real value is having the right Boss sizes, the right material choices, and the right support tools in one package. Common sizes can be used first, then refilled as needed.
Customers can reorder replacement Boss O-Rings from The O-Ring Store LLC when compartments run low. That means the customer does not need to replace the entire kit just because the most-used sizes are gone.
Price and Buying Value
This package is a smart purchase for shops that repair hydraulic equipment, service Boss fittings, or support field maintenance crews.
The buying value comes from:
- Less downtime
- Fewer emergency supply runs
- Faster repairs
- Better size organization
- Better O-Ring measurement support
- Material choice at the job site
- Cleaner installation with lubricant
- Easier O-Ring removal with the pick tool
- Refillable Boss O-Ring sizes
The customer is not only buying O-Rings. They are buying a faster repair process, better size confidence, and a practical way to keep Boss fitting repairs moving.
Before You Buy
Before ordering, confirm these details:
- Match the O-Ring size to the SAE Boss fitting or the original O-Ring
- Use Olypsys® Pro-Grid A4 (Letter) to help measure unknown O-Rings when size is not clear
- Match the material to the fluid, temperature, pressure, and environment
- Use Buna-N 90 for many common petroleum oil and hydraulic oil applications
- Use Viton®/FKM 90 when higher heat or better chemical resistance is needed
- Do not assume all rubber materials work in every fluid
- For critical applications, confirm material, hardness, certification, and traceability before use
If the repair has unknown chemicals, high temperature, unusual fluids, or strict compliance requirements, confirm compatibility before installation.
Why Buy From The O-Ring Store LLC
The O-Ring Store LLC is an ISO9001:2015 certified O-Ring and seal distributor. We make getting O-Rings easy.
Customers get more than a kit. They get clear sizing, practical product information, refill options, Olypsys® measurement support, and help from a team that works with O-Rings and seals every day.
Why customers buy from us:
- ISO9001:2015 certified quality system
- Practical O-Ring and seal knowledge
- Clear kit sizing and material information
- Olypsys® measurement tools and support
- Refill options for common sizes
- Helpful support from real people
- Fast service from a focused O-Ring distributor
- A team that understands downtime matters
The value is speed, accuracy, service, measurement support, and the ability to keep the kit working for the customer over time.
FAQ
What is this Boss O-Ring service package used for?
It is used for sealing, measuring, and repairing SAE straight thread Boss hydraulic fittings in equipment, pumps, valves, manifolds, and service trucks.
Is this kit SAE or metric?
This is an SAE Boss O-Ring service package. It includes SAE 900 series Boss O-Ring sizes.
What is the Olypsys® Pro-Grid A4 (Letter) used for?
It helps measure O-Rings so customers can identify the inside diameter, cross section, and size with more confidence using the Olypsys® measurement system.
What materials are included?
This package includes Buna-N 90 Boss O-Rings and Viton®/FKM 90 Boss O-Rings.
Can I use this with hydraulic oil?
Yes, Buna-N 90 is commonly used with many petroleum-based hydraulic oils. Viton®/FKM 90 can also be used in many oil and fuel applications where higher heat or chemical resistance is needed. Always confirm fluid compatibility.
Can I refill the kit?
Yes. Replacement Boss O-Rings can be reordered from The O-Ring Store LLC when individual compartments run low.
