000/+. , you actually don. Metric key keyway dimensions per iso/rtt3 js9 width Metric plated Metric woodruff keys are supplied to din 6888 / iso 3912 in c45k key. Gib head keys are specially manufactured machine keys with a projecting end that resembles the end of a gib and serves as a stop mechanism on a rotating shaft. 0mm. 1563″ Cut Width, 1/2″ Shank Dia, Straight Tooth 2. Woodruff Key Stock are typically made from metals like steel, brass, or aluminum which can be hardened to. 7mm, 3 x 13 x 5mm, 3 x 16 x 6. * These Width A values were set with the maximum keyseat (shaft) width as that figure which will receive a key with the greatest amount of looseness consistent with assuring the key's sticking in the keyseat (shaft). PRODUCTS; WHAT’S NEW; ABOUT; CATALOGUES. 99 $ 15 . Metric Woodruff Keys - 2mm X 3. The standard key size for a straight key in a shaft is one quarter the shaft diameter. Keyway standard dimensions keyseat pdf printer friendly information. Key Size 10 mm × 16 mm (10 Each) Plastic Box: 000000000: 000000:METRIC HSS SINGLE WOODRUFF CUTTERS. 99Woodruff Keys ANSI B17. Now let’s say. Part Width Height Length circ. Product. 1 offer from $19. Made from M2 HSS ALL 12MM SHANKS. 12mm. Keyway key parallel jis sizes tolerances 1301 mm 1996 pulley excerpt unit techKeyway metric Table aii-12. 6 6. 6x7 2x37xlO 25>01 x 10 16 4 x 65 x 16 4 x 75 x 19 5x65x 16 5x75x19 6 x 9 x 22 6xlOx25 Basic Size 1. 10 HSS Woodruff Key Cutters Set Metric Made Of German Imported M2 Grade HSS. March 2022 Drive type fastenings without taper action - Woodruff keys - Dimensions and application. Because the keyseat is circular, the key will self-adjust to angled. Standard External Metric Thread and Fastener Sizes M 0. 846. 33 per 100. Glarks 205Pcs 12 Sizes Woodruff Keys Assortment Carbon Steel Woodruff-Key Semi-Circular Keys Metric Set for Fasteners Mechanical Industry 4. All dimensions are given in inches. Brand New. Order Code: K72316. 99. KeyWay /Key Dimensions. Opens in a new window or tab. Referencing Figure 1, the Metric key size is W x T. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. 2mm. 607) In. Brant Akkan. 7mm 2mm x 5mm 2. Brand New. HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes. Torqbolt supply woodruff keys to DIN 6888 / ISO 3912 metric sizes and BS 46 Part 1 imperial sizes. 99. 0mm (Din 6888)10 x S. Ask Question. In stock and ready to ship. 757 as “Key Woodruff 90”. HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes - Woodruff semicircle Key - Half Moon Key - Keyway - Shaft Crank Key 4. Dimensions of parallel keys and taper keys. Metric; Imperial; Woodruff Keys . 9 1 3 x 3. 【15 Sizes Woodruff Key Assortment Set】 The Woodruff Key Repair Kits have 150pcs 15 sizes metric woodruff keys. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. WIDTH. All dimensions are given in inches. Glarks 205Pcs 12 Sizes Woodruff Keys Assortment Carbon Steel Woodruff-Key Semi-Circular Keys Metric Set for Fasteners Mechanical Industry 4. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. In October’s column, I mentioned the typical tolerance for key-ways. This is because even a very small deviation from the size does not combine with the hub. 5 2. FREE delivery Jun 8 - 30 . Grizzly H5606 9-Piece Woodruff Key Seat Set. 1-1943 Standard. 🥇Swpeet 155Pcs 17 Sizes 2mm 3mm 4mm 5mm 6mm 8mm 10mm 12mm Woodruff Keys Half Moon Semicircle Bond Key Hardware Metric Assortment Kit for Fasteners Mechanical Industry 🥇 WHY CHOOSE US? 💯 1, Nice selection, A perfect assortment of needed parts. A4 stainless steel are also available to order. 4 18 11 66 75 20 4. The sizes range from the commonly used 1/4, 1/8, 3/16 inch to metric measurements like 3mm, 4mm, 5mm, and larger variations such as 606, 404, and 406 woodruff keys. 7 10 9 . 1. 1) The tolerance zone for hub keyway width b for parallel keys with normal fit is ISO JS9 and with close fit ISO P9. Square keys. Add to a parts list. This item Hilitchi 155Pcs 17 Sizes Carbon Steel Woodruff Keys Half Moon Assortment Kit, Semicircle Bond Key Hardware Metric Assortment Kit, Woodruff Key-Crankshaft for Fasteners Mechanical Industry Stens 415-414 Woodruff Key Kit Includes 250 pieces, Includes the following 5 of #10 5/32" W x 7/8" L, 5 of #11 3/16" W x 7/8" L, 5 of #12 7/32" W x. 3 16 10 59 65 18 4. 47. Woodruff Keyways & Keys. Our 4375 Keyseat Cutter is stocked with ½” diameter steel. 6 6. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. 5mm x 2. 11058 Metric Woodruff Key 4. These keys have a rounded shape that makes them easy to remove when parts need to be taken apart frequently. 3 out of 5 stars 20 1 offer from $15. 56 $ 12. This allows the key to withstand great strain and is not prone to rolling over in the key seat like ordinary machine keys. Shop for Woodruff Keys in Fasteners. 2 + 0. 56 $ 12. Woodruff Keys - Metric. 99 Woodruff Keys Woodruff Keys are stocked as standard in 45+ key steel, with a minimum tensile strength of 60Kg/mm². Woodruff keys work well near shaft shoulders and on tapered shafts. Our pdfs can be found at the top of the page. 11060 Metric Woodruff Key 5. They provide the torque to drive the rotating component and help prevent unwanted slipping or movement. Flat & Hollow saddle keys;. 8 out of 5 stars 15. 0 out of 5 stars 10 $15. boeray 164pcs Woodruff Key Assortment Metric Set 17 Sizes Carbon Steel Woodruff-key Kit Woodruff Key-Crankshaft. 139 sold. Metric Woodruff Keys DIN 6888 5 x 6. 24. While working on the front of the crankshaft I needed some new Woodruff keys. ToolHub 9842 Woodruff Feather Key Assortment Set 80 Pc Metric 3 -6mm. Gib keys are usually made from cold drawn steel which is cut to length and the taper and head are milled to specific tolerances and then tumbled to provide a finished edge. For technical drawings and 3-D models, click on a part number. 25T. Machine keys are pre-cut lengths of metal that insert into the groove of a. Definition: Woodruff keys are semicircular, fitting partly into A*B circular segment keyway with the remainder fitting into a longitudinal slot keyway in the mating part. Product Features: Available in many different sizes and thicknesses; Conveniently packaged in a variety of piece counts to assist with both small and large projects; Easy to InstallWoodruff Key Search Results. com. 30. Buy It Now. 16 0. 99 $ 13. Amazon's Choice. 0 2 2 9 10 3 1. 99: ISO/TC 14: ISO 4156-1:2005. 5mm, 4. Measurements, Sizes, Shafts, Keyways. 854 Inch 0. On the now freed pulley, look for a semicircular piece inset into the shaft. All the sizes you need in one convenient kit! Features. A4 stainless steel are also available to order. Model # 881712. The recessed. 5x3. Metric and standard sizes are communicated differently. This key stock is undersized, so keys will fit slightly more loosely than standard keys and are best for inconsistent keyways. Flat. 0947 : 0. 8 6 6 23 30 8 3. metric woodruff keys are only available with round bottoms complete guide to woodruff keys keyways design web woodruff key is a flat semi circular or half moonA rectangular key is generally used for shaft diameter between 1” (25 mm) and 20” (500 mm) Generally, these have a reduced effect on the shaft due to its shallow keyway depth. Metric External Table Chart Thread Designations Sizes M 1. 859 Inch. £10. Wide range of sizes, material and finish available. They're easy to install and available in different sizes and thickness. They are designed to be installed deep into a shaft and remain firmly embedded. 9L Cummins Diesel Injection Pump to Gear Housing Gasket. +. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. Woodruff Keys. 99 $ 15 . The keyseat engages with the key on the part to prevent unwanted rotation of the part when it is mounted to the shaft. FREE delivery Tue, Nov 14 on $35 of items shipped by Amazon. OK, I guess the straight key is the way to go, then. 5 x 19 6 x 7. Carbon keys are normally made from cold drawn SAE-1035 steel and alloy keys normally are made from SAE 8630 steel and are heat treated to Rockwell "C" 40-50. 12mm. Save 66%. The circular. 5mm, 4 x 13 x 5mm, 4. Woodruff Keys are stocked in C45k key steel, with a minimum tensile strength of 60Kg/mm 2 . Woodruff key: [noun] a shaft key made in the form of a segment of a disk and used with shafts not more than 2¹/₂ inches in diameter. 2 out of 5 stars 108. In the Metric system it is common practice to specify the key size. Your firstname * Your lastname * Your email * Your message for us * Send message 0091-22-66157017 info@torqbolt. Choose from our selection of rectangle keys, including over 950 products in a wide range of styles and sizes. Technifast supply woodruff keys to DIN 6888 / ISO 3912 metric sizes and BS 46 Part 1 imperial sizes. Hillman. Stanho Non-Rok keys (formerly Standard Automotive keys) are specially designed woodruff keys but utilize an angled shape instead of the arch shape used in standard woodruff keys. 460pc Woodruff Key / Snap Ring / Roll Pin / E-Clip Assortment Set. 8 6 6 23 30 8 3. The sizes range from the commonly used 1/4, 1/8, 3/16 inch to metric measurements like 3mm, 4mm, 5mm, and larger variations such as 606, 404, and 406 woodruff keys. 3 12 8 45 50 14 3. British ISO Metric Screw Threads Designations. Metric & Multistandard Components Corp. • The woodruff key seat cutter is a circular cutter integral with a parallel shank for holding and driving having definite diameter and width with sides slightly concave designed for cutting seating in shafts for woodruff keys. 1⁄8: 0. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. 5 25 Depth Hub, Shaft,. Metric woodruff keys are measured in millimeters (ISO standard) or in micrometers in more. 5x16 5x6. NEIKO 50455A E-Clip Assortment Set | 300 PCS, 9 SAE Sizes, Heat Treated External Retaining Clips, 1/16" - 7/8 Inch | High Carbon Steel Circlip Kit, Anti Walk Washers, Retaining Rings. (Dimensions comply with DIN 6885/1) † Requires use of chamfered keys. 66. 4. Taper metric dimensions keyway key bs 1972 keyways keys. ex-gst. 6 mm (25 Each) Key Size 2 mm × 5 mm (25. 1260 :. 33. Its available in a wide selection of standard sizes and special face widths are also available with our 24-hour just-in-time service. 99 $ 22 . Woodruff Keys. Woodruff Keys - Metric. 99The sizes range from the commonly used 1/4, 1/8, 3/16 inch to metric measurements like 3mm, 4mm, 5mm, and larger variations such as 606, 404, and 406 woodruff keys. Metric module, side fit. 18-8 stainless steel key stock offers a balance of strength and corrosion resistance. Enquire. 5mmRustark 205Pcs 12 Sizes Woodruff Key Stock Assortment Kit Half Moon Semicircle Bond Key Flywheel Key Metric Hardware for Mechanical Industry Use ★ WHY CHOOSE US? 1. 99 $ 19. Phone: 1-716-791-6197. ) Choose from our selection of rectangle keys, including over 950 products in a wide range of styles and sizes. 95. 95 $ 15. For technical drawings and 3-D models, click on a. All of the woodruff keys are packed in a plastic box with a clear label size by sizes for portable and convenient to store. HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes - Woodruff semicircle Key - Half Moon Key - Keyway - Shaft Crank Key 4. Standard Metric Keys Keyways for Metric Bores with One Key;Woodruff Key Cutter Set (10PC) 3/8"-1" - Imperial HSS Coated in Alloy Box. Use the infographic below to learn which measurements are required to select the correct woodruff key sizes for metric woodruff keys, inch woodruff keys, and hi-pro woodruff keys. ASME B1. 5mm 3mm 4mm 5mm - Select Qty - Free P & P at the best online prices at eBay! Free shipping for many products!The following tables show standard dimensions for keys and their grooves. Bargain keycorp upgradesboeray 164pcs Woodruff Key Assortment Metric Set 17 Sizes Carbon Steel Woodruff-key Kit Woodruff Key-Crankshaft. Lock pulleys and gears securely with these woodruff keys Read More. Huyett carries keystock in a variety of materials to match the tolerances and mechanical strength you need. Examples of Woodruff keyseat cut- shown on page 869. Metric Key & Keyway Dimensions Per ISO/R773 – Js9 Width Tolerance « + Keyways will be furnished per ISO/R773 and Js9 width tolerance unless otherwise specified. Metric Keyseat cutters are available in either straight or staggered teeth to accommodate various machining methods. Price Each You can enter/change the number of items on the order form; 2x7: 2. 1⁄2 . 5 25 Depth Hub, Shaft,. 3. 76 7 EQS-B2-2 2. Woodruff keys, also called half-moon keys, are commonly found in machine tools and automotive applications. Assortment 2 of 2. Minimum keyseat width is that figure permitting the largest shaft. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. Key Size 10 mm × 16. WOODRUFF KEY KIT PIECES SIZE 20 20 20 20 20 20 20 2x2. $159. Detailed width tolerance information is best drawn. Add to Wish List. Radius R. Woodruff Keys Included: Container Type : Each: 1008-1045 Carbon Steel. Package Quantity: Strap Width: 3/32 in; 1/8 in; 5/32 in; 3/16 in. 7x10 2. Gates belts, hoses, and applications: standard & non-standard shaft keyShaft standard key sizes rectangular gates keys diameters most non std readily available Standard woodruff. Metric key keyway dimensions per iso/rtt3 js9 width Metric plated Metric woodruff keys are supplied to din 6888 / iso 3912 in c45k key. Metric – Rectangular B. STOREHOUSE Woodruff Key Assortment – 80 Pc. 6: 6. These sizes cater to different shaft diameters and keyway dimensions, ensuring a proper fit for your specific requirements. Check out our 4375 Keyseat Cutter – it was designed for small engine manufacturing and automotive companies where narrow-width slots are necessary. 2-1967 (R1998) - Engineers Edge. Opens in a new window or tab. Model # 881431. 95. for pricing and availability. FREE delivery Sat, Nov 4 on $35 of items shipped by Amazon. Or fastest delivery May 22 - 25 . Min. 19 Shaft and Arbor Class A and B . They are semi-circular, and fit into a Keyway shaped as a circular-segment in the shaft and a rectangular slot in the mating part. 🥇 Swpeet 150Pcs 15 Sizes 3mm 4mm 5mm 6mm 8mm 10mm Woodruff Keys Half Moon Semicircle Bond Key Hardware Metric Assortment Kit for Fasteners Mechanical Industry 🥇 WHY CHOOSE US? 💯 1, Nice selection, A perfect assortment of needed parts. 8 4 4 13 17 5 2. 0mm. The sizes range from the commonly used 1/4, 1/8, 3/16 inch to metric measurements like 3mm, 4mm, 5mm, and larger variations such as 606, 404, and 406 woodruff keys. +C $28. Sizes and availability for Woodruff Key in metric measurements, in Steel material. keyways /keys dimension in accordance with BS 4235-1:1972: Specification for metric keys and keyways - Parallel and taper keys . Glarks 205Pcs 12 Sizes Woodruff Keys Assortment Carbon Steel Woodruff-Key Semi-Circular Keys Metric Set for Fasteners Mechanical Industry 4. 【17 Sizes Woodruff Key Assortment Set】 The Woodruff Key Repair Kits have 155pcs 17 sizes woodruff keys. Discover more about our selection of Handi·Chek® fastener assortments in the Handi·Chek catalogThis Standard establishes a uniform relationship between shaft size and key size for parallel and taper keys retaining similar basic sizing as found in the withdrawn B17. 6 out of 5 stars 17 $20. $19. 5 mm 3 mm 4 mm 5 mm 6 mm 7 mm 8 mm 10 mm 12 mm 14 mm 16 mm 18 mm 20 mm 22 mm 24 mm 25 mm 28 mm. Also known as sine keys. Metric External Table Chart. 4660 or click here to contact us. 25 - M 1. New. Add to Cart. $15. AIMS Industrial is an authorised distributor of fasteners. The Woodruff keys is a semi-circular disc and fit into a circular recess in the shafts, which is machined by a Woodruffs keyway cutter. Size 1. 252M-1996 vwmøwrm Hub Key Shaft Section A-A Width Toleranceh Detail z Key Sizea ilxI,4x4 15x2. Add to Basket. 3. 00. They are useful for shaft end. Assortment 2 of 2. The tolerance zone for shaft keyway width b with normal fit is ISO N9 and with close fit ISO P9. Follow Us, Be a Champion. Work Shop Buddy Woodruff Key Metric Grab Kit (3 x 5 x 13 - 6 x 9 x 22m. 7mm - (Box of 5) - $4. 8 14 9 51 58 16 4. High Quality ---- Made of carbon steel material with high hardness and toughness, provides high corrosion resistance and wear resistance for a long-lasting use. 5 mm × 2. 4481 : 5⁄8 . 99 $ 22 . CONTENT: 3*5*13: 10pcs; 3*6. Woodruff Key Assortment, 80 Piece. assortments and fastener kits are available for clevis and bridge pins, electrical connectors, flat washers, hose clamps, key stock and machine keys, lock and flat washers, retaining rings, three-point-pins, and woodruff keys. 000/+. 6 mm (25 Each) Key Size 2 mm × 2. 95. Standard External Metric Thread and Fastener Sizes M 0. I cut the rough dimensions with a cut off wheel. Use them in light duty applications to connect gears and other components to shafts. S. 1 offer from $19. 4. Summary. FEATHER KEY ASSORTMENT 60 PIECE METRIC VARIOUS SIZES WOODRUFF HUBS DRIVE SHAFTS. HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes - Woodruff semicircle Key - Half Moon Key - Keyway - Shaft Crank Key 4. 0 2. 4235 : PART 1 : 1972Where: T = D + T2. HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes - Woodruff semicircle Key - Half Moon Key - Keyway - Shaft Crank Key. In the Metric system it is common practice to specify the key size. 0 x 9. Woodruff Keys - Metric - Nordex, Inc. Keyway key parallel jis sizes tolerances 1301 mm 1996 pulley excerpt unit techKeyway metric Table aii-12. 25 - M 1. Metric Key Form A. Choose from our selection of 3mm keys in a wide range of styles and sizes. Woodruff Keys are an alternative to Parallel Keys. Use them in light duty applications to connect gears and other components to shafts. 7x10 3x3. 2 Shaft Key. 0 out of 5 stars 2 1 offer from $20. 6 out of 5 stars 66. FREE delivery Thu,. 80pc WOODRUFF KEY ASSORTMENT METRIC VARIOUS SIZES 3mm To 6mm Width. PC0272. Keyway metric key iso dimensions standard keyways keys r773 pdf bores shaft hub. Rectangular-faced keys are used for larger shaft diameters and square keys are used for shafts smaller than 6. Metric keys conform to DIN 6888 standards. Parallel keys are rectangular shapes with ends that are square (DIN-6885-B), round (DIN-6885-A), or both (DIN-6885-AB). HaSaoMoi 200pcs Metric Woodruff Key Assortment Kit with 15 Most Popular Sizes. W = d / 4 [clarification needed] H = 2d / 3 [clarification needed]. 76 7. Keystock is a versatile raw material used to make many types of machine keys, pins, gears, and for conducting quick field repairs on machine keys and shafts. BOXTAC. 20. Our carbon keys are normally made from cold. #5 · Mar 13, 2010. The key seat has to be precisely cut according to the key size to accommodate the key and prevent any interference between the key height and the depth of the host shaft’s key seat. 5mm. Only 8 left in stock - order soon. 1 offer from $22. 3810. Are there any standards for Metric bores and / or keyways? There many standards that cover the topics of metric bore tolerances, fits and keyway sizes. 70. Stainless steel grade A4 woodruff keys are also available to order. The keyway dimensions are also different from the English system. 0mm (Din 6888)10 x S. 00:00 Intro00:32 Metric keys01:42 Inch keys Per BS 4235-1:1972: Specification for metric keys and keyways – Parallel and taper keys. 5mm (Din 6888)10 x S. The sizes range from the commonly used 1/4, 1/8, 3/16 inch to metric measurements like 3mm, 4mm, 5mm, and larger variations such as 606, 404, and 406 woodruff keys. 76 2 0. Standard External Metric Thread and Fastener Sizes M 0. America's online Screw, Bolt and Fastener Supplies superstore! Frequently bought together. system. 3 out of 5 stars 19 1 offer from $15. Woodruff keys, identifiable by their half-moon shape, are measured two ways depending on if it is an imperial or metric key. 6 out of 5 stars 66 #1 Best SellerWOODRUFF KEYS WITHOUT PINS. 3 8 7 31 38 10 3. Metric Standard Parallel Keyway and Key Sizes Shaft Diameter (mm) Keyway (mm) Key (mm)* From To Width (W) Depth (h) Width (W) Depth (T) 6 8 2 1. For more information about our standard woodruff keys, call us today at 724. British ISO Metric Screw Threads Designations. 5 mm × 2. Part Width Height Length circ. Special sizes and materials suh. Glarks 205Pcs 12 Sizes Woodruff Keys Assortment Carbon Steel Woodruff-Key Semi-Circular Keys Metric Set for Fasteners Mechanical Industry. Metric woodruff keys are supplied to din 6888 / iso 3912 in c45k keyKeyway hallite Keyway chartShaft keys. Made of solid carbide, these keyseat cutters are harder, stronger, and more wear resistant than high-speed steel for the longest life and best finish on hard material. The Complete Tool Making Authority® Quick Navigation. Quickview. 99Amazon. boeray 164pcs Woodruff Key Assortment Metric Set 17 Sizes Carbon Steel Woodruff-key Kit Woodruff Key-Crankshaft. These keys have a rounded shape that makes them easy to remove when parts need to be taken apart frequently. For technical drawings and 3-D models, click on a part number. com. K72316 1 of 2. Keyway Dimensions for Metric Woodruff Keys ASME 1318. 11060 Metric Woodruff Key 5. Keadic 205Pcs 12 Sizes Metric Woodruff Key Assortment Set, Carbon Steel Half Moon Gear Shaft Drive. Shaft with Two Keyways Torque Applied Deformation and Stress Equations. In stock and ready to ship. Key bar std size. They're easy to install and available in different sizes and thickness. The circular segment can be cut directly by plunge cutting with a circular Woodruff cutter without any reliefs. There is also a ‘Key Number’ system that is mentioned in the table below as an alternative way of specification. $1099. 66 2. Manufactured from C45k key steel (plain finish) Conforms to DIN 6888 / ISO 3912 Made to minus tolerances (h9 on width and h12 on height) Sizes are width x height x diameterKey standard sizes shaft failure theories ppt powerpoint presentation diaMetric woodruff keys are supplied to din 6888 / iso 3912 in c45k key Keyway chartKeys standard metric keyways mechanical. 8%. For steel hammers, insulate the shaft, nut, and bolt before striking. K72316 - Metric Woodruff Key Assortment 80 Piece. This product is perfect for those who need a variety of sizes of woodruff keys in one package. VIEW ALL RS. Shaft key standard sizes rectangular gates keys std diameters most non readily availableMetric woodruff keys are supplied to din 6888 / iso 3912 in c45k key. 53. Product variants. Woodruff. 4 3 3 11 12 4 1. Choose from keys in a variety of sizes, lengths, and coatings at House of Metrics. There are numerous cutter widths and cutting sizes available for key cutters, and a pre-cut key stock is offered in both metric and standard inch sizes.