Exotic Wood Stiffness Ranked: MOE and River Table Sag

Understanding Wood Stiffness and Span Design in Tabletops

When engineering a wood and epoxy tabletop, visual grain and color often take priority during slab selection. However, for large dining tables, conference surfaces, or desks that rest on end bases without intermediate framework, mechanical stiffness is a critical physical property. Modulus of elasticity (MOE) represents a material’s intrinsic resistance to bending or deflecting elastically under applied force.

Technical wood evaluations compile structural properties under standardized equilibrium moisture content. The figures presented here originate from CIRAD (specifically the CIRAD Tropix 7 technical series), which measures mature timber properties including modulus of elasticity in megapascals (MPa) adjusted to 12% moisture content, alongside calculated conversions in pounds per square inch (psi).

Why Modulus of Elasticity Controls Span Sag

Tabletops spanning long distances between leg trestles or metal frames behave as horizontal beams subjected to both permanent dead loads (the mass of the wood and cured resin) and intermittent live loads (dishes, equipment, or resting elbows). When a tabletop lacks a rigid perimeter apron or continuous under-table steel stiffener, resistance to center deflection depends directly on two variables: the slab’s total thickness and the inherent modulus of elasticity of the species.

A timber with a high modulus of elasticity undergoes minimal downward flexure when loaded across an unsupported span. Conversely, selecting a species with low stiffness means the same tabletop thickness and span will exhibit noticeably higher sag under load. Over extended spans, excessive deflection not only creates an unlevel working plane but can also concentrate mechanical tension along glued seams and resin-wood bond lines.

The Stiffest Exotic Woods

At the top of the stiffness spectrum are dense tropical hardwoods whose longitudinal fibers provide extreme structural resistance to bending. These species excel across open spans where minimal deflection is required without requiring excessive slab thickness:

• Wamara: Leads the compilation with an MOE of 32,700 MPa (about 4,743,000 psi).
• Preciosa: Reaches 30,230 MPa (about 4,384,000 psi).
• Bitis: Follows at 29,500 MPa (about 4,279,000 psi).
• Keranji: Tested at 28,460 MPa (about 4,128,000 psi).
• Muirapiranga / Bloodwood: Measures 28,130 MPa (about 4,080,000 psi).
• Abiurana vermelha: Reaches 28,000 MPa (about 4,061,000 psi).
• Snakewood: Records 27,030 MPa (about 3,920,000 psi).
• Congotali: Registers 26,700 MPa (about 3,873,000 psi).
• Cumaru / Tonka: Measures 26,610 MPa (about 3,859,000 psi).
• Manniballi: Records 26,540 MPa (about 3,849,000 psi).
• Angelim vermelho: Reaches 26,280 MPa (about 3,812,000 psi).

For custom builders, incorporating timber from this elite upper bracket ensures that the wooden components of the top provide exceptional rigidity against self-weight and surface pressure across wider leg spacings.

The Least Stiff Exotic Woods

At the opposite end of the spectrum are softer, lighter species that yield significantly lower resistance to bending. When spanning long gaps between supports, these timbers deflect much more readily:

• Sumauma: Anchors the lower limit with an MOE of 5,080 MPa (about 737,000 psi).
• Ceiba: Measures 5,130 MPa (about 744,000 psi).
• Erimado: Records 5,200 MPa (about 754,000 psi).
• Kapokier: Tests at 6,060 MPa (about 879,000 psi).
• Pashaco / paricá: Reaches 7,800 MPa (about 1,131,000 psi).
• Alstonia: Yields 8,090 MPa (about 1,173,000 psi).
• Suren: Registers 8,400 MPa (about 1,218,000 psi).
• African cordia: Measures 8,600 MPa (about 1,247,000 psi).
• Peruvian Walnut: Evaluated at 8,720 MPa (about 1,265,000 psi).
• Radiata Pine (European Plantation): Records 8,750 MPa (about 1,269,000 psi).
• East african bombax: Reaches 8,760 MPa (about 1,271,000 psi).
• Maritime Pine: Tested at 8,800 MPa (about 1,276,000 psi).
• Cryptomeria: Registers 8,900 MPa (about 1,291,000 psi).
• Pulai: Measures 8,930 MPa (about 1,295,000 psi).
• Antiaris: Reaches 9,000 MPa (about 1,305,000 psi).

If utilizing species from this low-stiffness category over long spans, builders must account for increased deflection by designing additional base bracing, shortening the unsupported gap, or integrating intermediate substructures.

How Epoxy River Width Affects Span Deflection

In a composite river table, the overall stiffness across the span is a hybrid behavior between the continuous wood slabs and the central polymer channel. Clear casting epoxies possess mechanical behaviors distinct from the directional grain of dense hardwood slabs. Hardwood timber features long, parallel cellulose fibers that inherently resist longitudinal bending along the grain.

As the epoxy river width widens relative to the wooden slabs, a larger proportion of the tabletop’s cross section consists of cured resin rather than stiff wood fiber. Qualitatively, a very wide epoxy channel reduces the total contribution of the timber’s longitudinal stiffness across the unsupported distance. In contrast, narrow rivers flanked by wide, stiff slabs like Wamara, Preciosa, or Cumaru retain the structural characteristics of solid timber beams. Always review the resin manufacturer’s technical data sheet for product recommendations regarding structural load distribution, pour thicknesses, and base support requirements.

Wood	Modulus of elasticity (MPa)	About psi (calc.)
Wamara	32,700	4,743,000
Preciosa	30,230	4,384,000
Bitis	29,500	4,279,000
Keranji	28,460	4,128,000
Muirapiranga / Bloodwood	28,130	4,080,000
Abiurana vermelha	28,000	4,061,000
Snakewood	27,030	3,920,000
Congotali	26,700	3,873,000
Cumaru / Tonka	26,610	3,859,000
Manniballi	26,540	3,849,000
Angelim vermelho	26,280	3,812,000
Rosewood Para	26,150	3,793,000
Araracanga	26,140	3,791,000
Eveuss	25,620	3,716,000
Uchy	25,550	3,706,000
Andok	25,060	3,635,000
Massaranduba	24,410	3,540,000
Chengal	24,300	3,524,000
Tamarindo (Groçai-rosa)	24,000	3,481,000
Alep	23,390	3,392,000
Yellow balau	22,940	3,327,000
Eyoum	22,700	3,292,000
Billian	22,690	3,291,000
Pakuri	22,610	3,279,000
Tanimbuca	22,380	3,246,000
Okan	22,260	3,229,000
Moral	21,900	3,176,000
Ozouga	21,770	3,157,000
Tatajuba	21,490	3,117,000
Ovangkol	21,470	3,114,000
Ekki	21,420	3,107,000
Manilkara	21,300	3,089,000
Dina	21,290	3,088,000
Mutenye	21,250	3,082,000
Wenge	21,050	3,053,000
Moabi	21,040	3,052,000
Itauba	21,020	3,049,000
Angelim pedra	20,870	3,027,000
Goiabao	20,600	2,988,000
Cabreuva	20,560	2,982,000
Pau mulato	20,560	2,982,000
Giam	20,500	2,973,000
Pyinkado	20,500	2,973,000
Macacauba	20,490	2,972,000
Bodioa	20,290	2,943,000
Grenadillo / Grenadille d’Afrique	20,250	2,937,000
Angelin	20,170	2,925,000
Merpauh	20,060	2,909,000
Sapucaia	20,000	2,901,000
Wacapou	19,780	2,869,000
Kembang semangkok	19,710	2,859,000
Angelim amargoso	19,500	2,828,000
Resak	19,500	2,828,000
Coula	19,490	2,827,000
Tali / Missanda	19,490	2,827,000
Yellowheart	19,460	2,822,000
Mandioqueira	19,400	2,814,000
Sougué	19,340	2,805,000
Mubala	19,160	2,779,000
Cardeiro / Cedrinho	19,140	2,776,000
Timborana	19,120	2,773,000
Baracara	18,940	2,747,000
Mora	18,940	2,747,000
Ananta	18,730	2,717,000
Melunak	18,700	2,712,000
Brown sterculia	18,670	2,708,000
Gheombi	18,640	2,704,000
Olène	18,550	2,690,000
Niove	18,510	2,685,000
Rengas	18,500	2,683,000
Ceylon Satinwood	18,500	2,683,000
Difou	18,490	2,682,000
Longui	18,490	2,682,000
Wallaba	18,450	2,676,000
Basralocus	18,350	2,661,000
Cupiuba	18,190	2,638,000
Macucu de paca	18,170	2,635,000
Alumbi	18,060	2,619,000
Limbali	18,010	2,612,000
Macassar Ebony (Ebène Veinée d’Asie)	18,000	2,611,000
Tamalan Rosewood	18,000	2,611,000
Tasmanian oak	18,000	2,611,000
Vésámbata	18,000	2,611,000
Beli	17,840	2,587,000
Simpoh	17,700	2,567,000
Piquiarana	17,640	2,558,000
Zebrano	17,520	2,541,000
Amesclào	17,490	2,537,000
Kasai	17,330	2,514,000
Curupixa	17,300	2,509,000
Freijo	17,270	2,505,000
Piquia	17,270	2,505,000
White sterculia	17,110	2,482,000
Djedoe	17,100	2,480,000
Batibatra	17,090	2,479,000
Guariuba	17,060	2,474,000
Mukulungu	17,060	2,474,000
Afzelia	17,020	2,469,000
Idéwa	16,910	2,453,000
Sepetir	16,900	2,451,000
Alan / Alan-Batu	16,860	2,445,000
Lati	16,830	2,441,000
Red balau	16,670	2,418,000
Keruing	16,610	2,409,000
Padauk amboina	16,600	2,408,000
Ohia	16,500	2,393,000
Cow tree	16,380	2,376,000
Merkus pine	16,370	2,374,000
Punah	16,300	2,364,000
Diania	16,200	2,350,000
Wamba	16,120	2,338,000
Safukala	16,090	2,334,000
Kanda rose	16,060	2,329,000
Oboto	16,040	2,326,000
Angoa	16,030	2,325,000
Manchiche	16,000	2,321,000
Garapa	15,880	2,303,000
African Padauk	15,870	2,302,000
Pau marfim	15,850	2,299,000
Melancieira	15,810	2,293,000
Pyinma	15,690	2,276,000
Sterculia	15,690	2,276,000
Vêne	15,670	2,273,000
Manil / Manni	15,630	2,267,000
Angueuk	15,610	2,264,000
Black Guarea (Bossé Foncé)	15,600	2,263,000
Merawan	15,600	2,263,000
Sonokeling Rosewood	15,600	2,263,000
Cedrinho	15,520	2,251,000
Durian	15,500	2,248,000
Kelat	15,460	2,242,000
Merbau	15,440	2,239,000
Perupok	15,380	2,231,000
Jequitiba	15,330	2,223,000
European Beech	15,300	2,219,000
Pucté	15,300	2,219,000
Red grandis	15,200	2,205,000
Dabema	15,190	2,203,000
Catucaém / louro faia	15,160	2,199,000
Dakama	15,100	2,190,000
Ossabel	15,040	2,181,000
Mumuli	14,960	2,170,000
Tchitola	14,960	2,170,000
Jacareuba	14,840	2,152,000
Bintangor	14,800	2,147,000
Ayan	14,740	2,138,000
Ossimiale	14,740	2,138,000
Gerutu	14,710	2,134,000
Bilinga / Opepe	14,660	2,126,000
Douka	14,600	2,118,000
Maporokon	14,600	2,118,000
Etimoe	14,560	2,112,000
Tauari	14,500	2,103,000
Mengkulang	14,450	2,096,000
Niangon	14,430	2,093,000
Kurokai	14,350	2,081,000
Gommier	14,320	2,077,000
European Silver Fir	14,300	2,074,000
Louro vermelho	14,170	2,055,000
Osanga	14,100	2,045,000
Gombé towé	14,090	2,044,000
Andoung	14,010	2,032,000
Landa	14,010	2,032,000
Keledang	14,000	2,031,000
Brazil nut	13,950	2,023,000
Ozigo	13,820	2,004,000
Coconut wood	13,800	2,002,000
Ekop	13,760	1,996,000
Abarco	13,720	1,990,000
Aningeria	13,690	1,986,000
Muhuhu	13,630	1,977,000
Mansonia	13,620	1,975,000
Makoré	13,450	1,951,000
Onzabili	13,450	1,951,000
European Sweet Chestnut	13,300	1,929,000
European Oak	13,300	1,929,000
Ossoko	13,300	1,929,000
Utile	13,240	1,920,000
Dukali / amapa	13,140	1,906,000
Pterygota	13,140	1,906,000
Mambode	13,100	1,900,000
Izombe	13,090	1,899,000
Igaganga	13,060	1,894,000
Danta	13,020	1,888,000
Sycamore Maple (Great Maple)	13,000	1,885,000
Iatandza	13,000	1,885,000
Mersawa	12,930	1,875,000
European Ash	12,900	1,871,000
Owui	12,900	1,871,000
Scots Pine	12,900	1,871,000
Okwen	12,880	1,868,000
Berlinia	12,870	1,867,000
Essia	12,870	1,867,000
Iroko	12,840	1,862,000
Haldu	12,770	1,852,000
Nyatoh	12,770	1,852,000
Odoko	12,750	1,849,000
Scented Guarea (Bossé Clair)	12,650	1,835,000
Morototo	12,600	1,827,000
Ekoune	12,460	1,807,000
Copaiba	12,450	1,806,000
Dalli	12,430	1,803,000
Olon	12,410	1,800,000
Ariella	12,400	1,798,000
White seraya	12,370	1,794,000
Benguet pine	12,300	1,784,000
Louro branco	12,290	1,783,000
Mango (Machang)	12,250	1,777,000
Kanda brun	12,040	1,746,000
Quaruba	11,980	1,738,000
European Spruce	11,900	1,726,000
European Larch	11,800	1,711,000
European Walnut	11,800	1,711,000
Rubberwood	11,760	1,706,000
Kumbi	11,750	1,704,000
Mountain Pine (Hooked Pine)	11,720	1,700,000
Nieuk	11,700	1,697,000
Senegal mahogany	11,650	1,690,000
Faveira	11,510	1,669,000
Gombé rouge	11,360	1,648,000
Idigbo	11,350	1,646,000
Patula pine	11,350	1,646,000
Sesendok	11,280	1,636,000
Kauri	11,240	1,630,000
Kosipo	11,190	1,623,000
Jacaranda	11,100	1,610,000
Musizi	11,030	1,600,000
Abura	11,020	1,598,000
Cerejeira	10,980	1,593,000
Gedu nohor	10,980	1,593,000
Agba	10,920	1,584,000
Cedrorana	10,900	1,581,000
Geronggang	10,830	1,571,000
Black wattle	10,800	1,566,000
Kedondong	10,790	1,565,000
African canarium	10,490	1,521,000
African walnut	10,460	1,517,000
Anzèm / nténé	10,340	1,500,000
European Cherry	10,200	1,479,000
Ilomba	10,130	1,469,000
Atlas Cedar	10,100	1,465,000
Capomo	10,070	1,461,000
Marupa	10,070	1,461,000
Jelutong	10,040	1,456,000
European Poplar	9,800	1,421,000
Canon ball	9,670	1,403,000
Guanacaste	9,650	1,400,000
Sandbox	9,600	1,392,000
Ogea	9,550	1,385,000
Ovoga	9,320	1,352,000
Magas	9,120	1,323,000
Yemane	9,120	1,323,000
Antiaris	9,000	1,305,000
Pulai	8,930	1,295,000
Cryptomeria	8,900	1,291,000
Maritime Pine	8,800	1,276,000
East african bombax	8,760	1,271,000
Radiata Pine (European Plantation)	8,750	1,269,000
Peruvian Walnut	8,720	1,265,000
African cordia	8,600	1,247,000
Suren	8,400	1,218,000
Alstonia	8,090	1,173,000
Pashaco / paricá	7,800	1,131,000
Kapokier	6,060	879,000
Erimado	5,200	754,000
Ceiba	5,130	744,000
Sumauma	5,080	737,000

Data compiled by BigEpoxy from individual CIRAD Tropix 7 technical sheets (average values for mature wood).

Sources

• CIRAD Tropix 7 technical sheets (index)

Published October 31, 2026. Sources are linked in the text.

Header image: original graphic by BigEpoxy.com.