NEIKO 50400A Stainless Steel Lock and Flat Washer Assortment | 350 Piece Set | 12 Different Sizes in Spring Lock and Flat Design | Prevent Loose Fasteners - style: Washer
NEIKO 50400A Stainless Steel Lock and Flat Washer Assortment | 350 Piece Set | 12 Different Sizes in Spring Lock and Flat Design | Prevent Loose Fasteners - style: Washer
About this item
- GALVANIZED STAINLESS STEEL: These lock and flat washers provide excellent protection and security for nuts and bolts. They are made with galvanized stainless steel for long-term use and outstanding durability.
- VERSATILE & COMPATIBLE: These assorted washers come in multiple sizes to fit all your screws, nuts, and bolts. Each washer features a solid bearing surface to prevent the nut or bolt head from tearing through the material.
- OPTIMAL SURFACE AREA: Each stainless-steel flat or lock washer easily deflects the screw or bolt load, spreading the weight evenly for a secure and sure fit. These washers for screws and bolts are ideal for use at home or in the workshop.
- THE RIGHT SIZE: This set of washers contains a wide variety of sizes. It includes lock washers in sizes #6, #8, #10, 1/4", 5/16", and 3/8" and flat washers in sizes #6, #8, #10, 1/4", 5/16", and 3/8".
- CONVENIENT STORAGE: Keep your washers ready for your next home or automotive project. This 350-piece set comes in a convenient, sturdy plastic box with divided compartments for easy storage and an inside lid display for easy organization.
Overview
- Material: Stainless Steel
- Outside Diameter: 0.38 inches
- Washer Type: Flat
- Exterior Finish: Stainless Steel
- Item Thickness: 0.05 inches
Couldn't load pickup availability
Low stock: 10 left
View full details

Reviews
-
⭐⭐⭐⭐⭐
Hannah Miller — Seattle, Washington
I ordered several science activity supplies for projects at home. The product descriptions made it easier to compare the available options, and everything fit neatly into our learning space. Stemora made finding tools for hands-on activities feel simple and organized. -
⭐⭐⭐⭐⭐
Daniel Foster — Austin, Texas
I found a useful selection of electronics and robotics accessories for a beginner project. It was convenient to browse related components in clearly organized categories. I would consider shopping here again when planning another maker activity. -
⭐⭐⭐⭐⭐
Lauren Bennett — Denver, Colorado
The measurement and observation tools I selected worked well for the classroom activities I had planned. I especially appreciated being able to review the product details before ordering and choose items that matched the lesson requirements. -
⭐⭐⭐⭐⭐
Jason Parker — Portland, Oregon
I purchased a few storage items and small tools for organizing my maker workspace. The products helped keep components, wires, and project materials easier to sort and access. The overall shopping experience was straightforward and convenient.
New Arrivals
-
Double Sided LF HASL Perf Board, PCB Board, Electronic Circuit Board for DIY Prototype Circuit, FR4, Plated Through Hole Solder Prototype Board, ST-PERF-1-4 (1" x 4" - 2 Pack) - style: 1" x 4" - 2 Pack
Regular price $14.09 USDRegular priceSale price $14.09 USD -
2 Pcs Small Magnetic Board, Cute Magnet Display Stand for Tabletop - color: 2pcs Purple and White
Regular price $44.80 USDRegular priceSale price $44.80 USD -
Double Sided LF HASL Perf Board, PCB Board, Electronic Circuit Board for DIY Prototype Circuit, FR4, Plated Through Hole Solder Prototype Board, ST-PERF-1-3 (1" x 3" - 2 Pack) - style: 1" x 3" - 2 Pack
Regular price $12.43 USDRegular priceSale price $12.43 USD -
Glass Stirring Rods 5.4 Inch Clear Glass Teaspoon Stirrers Long Handle
Regular price $13.26 USDRegular priceSale price $13.26 USD -
Halloscume 4 Sets Bug Catcher for Kids Insect Catching Kit, Green - color: Green
Regular price $43.14 USDRegular priceSale price $43.14 USD -
Double Sided LF HASL Perf Board, PCB Board, Electronic Circuit Board for DIY Prototype Circuit, FR4, Plated Through Hole Solder Prototype Board, ST-PERF-1-2 (1" x 2" - 2 Pack) - style: 1" x 2" - 2 Pack
Regular price $11.44 USDRegular priceSale price $11.44 USD -
2 Pcs Small Magnetic Board, Cute Magnet Display Stand for Tabletop - color: 2pcs Pink and White
Regular price $41.48 USDRegular priceSale price $41.48 USD -
Rhino Grid Sheet for under a Self Healing 4'x8' Cutting Mat (Grid Sheet for under a Mat - NOT to Be Cut On) - color: Grid Sheet for under a mat - NOT to be cut on
Regular price $165.98 USDRegular priceSale price $165.98 USD -
Wow Sports Super Inflatable Lawn Water Slide - 25 ft - Zigzag Sprinklers
Regular price $248.98 USDRegular priceSale price $248.98 USD -
Double Sided LF HASL Perfboard, PCB Electronic Circuit Board for DIY Prototype Circuit, FR4, Plated Through Hole Solder Prototype Board, ST-PERF-1-1 (1" x 1" - 4 Pack) - style: 1" x 1" - 4 Pack
Regular price $13.26 USDRegular priceSale price $13.26 USD -
MiOYOOW DIY Remote Control Car Kit, STEM Soldering Practice Kit for School - color: Remote Control Car Kit
Regular price $24.88 USDRegular priceSale price $24.88 USD -
Double Sided ENIG Perf Board, PCB Board, Electronic Circuit Board for DIY Prototype Circuit, FR4, Plated Through Hole Solder Prototype Board, ST-PERF-3-3 (3" x 3") - style: 3" x 3"
Regular price $12.43 USDRegular priceSale price $12.43 USD -
Self Healing 4'x8' Rhino Cutting Mats - NO GRID - color: Blank, No Grid
Regular price $393.40 USDRegular priceSale price $393.40 USD -
17 PCS Bug Catching Kit Bug Catcher for Kids, Princess Dress Up Shoes Set
Regular price $52.19 USDRegular priceSale price $52.19 USD -
United Scientific Supplies 100-183 "Lily Meiosis, Second Meiotic Division (Plant Cell Meiosis)" Prepared Microscope Slide
Regular price $32.32 USDRegular priceSale price $32.32 USD -
MiOYOOW Line Following Robot Car Kit, Beginners Smart Car Soldering Practice Kit STEM Educational Electronics Soldering Projects for School and Home Learning - TT Motor - color: 1 Pack-soldering Tracking Car(tt Motor)
Regular price $16.58 USDRegular priceSale price $16.58 USD -
Self Healing 4'x8' Rhino Cutting Mat with separate Grid Sheet - color: Blank with grid sheet
Regular price $473.25 USDRegular priceSale price $473.25 USD -

C4Labs Zebra Pico W Case – for the Raspberry Pi Pico W/Pico 2 / Pico 2W - Single Pack - size: Single
Regular price $18.24 USDRegular priceSale price $18.24 USD
FAQ
What types of products does Stemora offer?
Stemora offers supplies for science experiments, microscopy, biology learning, measurement, laboratory organization, electronics, robotics, coding education, 3D printing, maker projects, and classroom activities. Available products and specifications may change over time.
Are Stemora products suitable for children?
Recommended ages vary by product. Please review the product description, manufacturer guidance, included warnings, and required skill level before purchasing. Products containing small parts, tools, electrical components, glass, or chemicals may not be suitable for young children.
Is adult supervision required?
Adult supervision is recommended for children and students, especially when using electrical components, sharp tools, heated equipment, glassware, small parts, or experiment materials. Customers are responsible for following all product instructions and safety precautions.
Can these products be used at home and in classrooms?
Many products may be suitable for classrooms, home learning, science projects, maker spaces, and hobby activities. Suitability depends on the specific product, learning environment, user experience, and intended activity.
How can I check what is included with a product?
Please review the product title, description, specifications, images, package quantity, and included-components section before ordering. Items shown for demonstration or scale in product images may not always be included.
How do I know whether an electronic or robotics part is compatible?
Check the listed dimensions, voltage, connector type, board compatibility, operating requirements, and supported platforms. Compatibility is not guaranteed unless it is specifically stated on the product page. Contact us before ordering if you need clarification.
When will I receive tracking information?
Tracking information is generally provided within 3–5 business days after an order is confirmed. In some cases, processing may take approximately 7–8 business days. Delivery may require an additional 4–5 business days after tracking becomes available, depending on the carrier and destination.
Why did my order arrive in separate packages?
Products in the same order may be shipped from different fulfillment locations. As a result, items may arrive separately and have different tracking numbers. You will not be charged additional shipping fees solely because an order is divided into multiple packages.
Can I change or cancel my order?
Contact us as soon as possible at vaioamaonaoak@gmail.com. We will try to assist, but changes or cancellations cannot be guaranteed once an order has entered processing or has been shipped.
What should I do if an item arrives damaged, defective, or incorrect?
Contact us promptly at vaioamaonaoak@gmail.com with your order number, a description of the issue, and clear photographs of the item, packaging, and shipping label. Please retain the product and original packaging while we review your request. Eligibility and available resolutions are subject to our Return & Refund Policy.
Blog posts
View all-
Arduino Wiring Errors: 7 Mistakes Beginners Mak...
Troubleshooting Arduino wiring errors becomes easier when you know where to look first. Learn how to identify common breadboard, power, polarity, grounding, and pin-assignment mistakes in beginner electronics projects
Arduino Wiring Errors: 7 Mistakes Beginners Mak...
Troubleshooting Arduino wiring errors becomes easier when you know where to look first. Learn how to identify common breadboard, power, polarity, grounding, and pin-assignment mistakes in beginner electronics projects
-
The Beginner’s Wiring Mistakes That Can Quietly...
Learn how to troubleshoot common Arduino wiring errors in beginner electronics projects. Discover practical breadboard, LED, sensor, power, and grounding checks that make STEM maker projects easier to debug.
The Beginner’s Wiring Mistakes That Can Quietly...
Learn how to troubleshoot common Arduino wiring errors in beginner electronics projects. Discover practical breadboard, LED, sensor, power, and grounding checks that make STEM maker projects easier to debug.
-
Arduino Wiring Errors: A Step-by-Step Guide to ...
Learn how to troubleshoot common Arduino wiring errors with a practical step-by-step process covering power, ground, breadboards, LEDs, sensors, signals, and testing. Build stronger electronics skills while turning circuit failures...
Arduino Wiring Errors: A Step-by-Step Guide to ...
Learn how to troubleshoot common Arduino wiring errors with a practical step-by-step process covering power, ground, breadboards, LEDs, sensors, signals, and testing. Build stronger electronics skills while turning circuit failures...
















